So I've been reading up on CPU and HS lapping and I decided to give it a go.  I used 2 guides to assist me along the way:
 
http://www.overclockersclub.com/guides/lapping/ as a heatsink guide and http://forums.legitreviews.com/about10788.html as a CPU guide.
 
I went out and bought some 400, 800, 1000, and 2000 grit sandpaper which was surprisingly hard to find.  I thought for sure Wal-Mart, Menards, or Home Depot would have them, but after I struck out at those places I wandered into a Murray's Auto Parts and got what I needed.
 
So, onto the good stuff. As you can see the Q6600 is overclocked to 3.4ghz, It usually runs at 3.6ghz but after seeing these temps I wanna step it down till the Arctic Silver 5 settles. I took some screens of my computers temps from Coretemp as a reference.  Prime95 is used to set load.
Idle Before: 57, 58, 54, 54

 
Load Before: 81, 81, 75, 77

 
So needless to say I was getting a little worried.  After a few hours of carefully lapping up to 2000 grit I have a shiny Q6600 and a very shiny Arctic Freezer 7 pro.  As it turns out, the Q6600 was pretty Convex (budging in the middle), and the Freezer 7 was somewhat concave (bubbled inward) in the middle.  Sorry I dont have a digital camera to document the work.  I reapplied some Arctic Silver 5 and ran Coretemp to see the immediate results:
 
Idle right after: 59, 59, 54, 55

 
Load right after: 72, 71, 66, 67

 
As you can see my idle temps stayed that same if not increased 1 degree.  More importantly, my load temps dropped 10 degrees immediately!  Now the Arctic Silver 5 is still fresh and needs to be burned in to get maximum gains, so I will be updating this thread at the 3 day, 1 week, and 2 week mark with a graph to show my results.  
 
If anyone was wondering if lapping is worth it, all I have to say is apparently yes!

thats very impressive. i have a coolermaster 212 and i would consider lapping that bad boy. i dont know if i am ready to lap my cpu. i dont really want to risk killing it. more importantly, it is still under warranty as well. the cpu would be much harder to seller on ebay since all the numbers engraved are gone.

Thats amazing... i wouldnt have though there would be that much difference... I just went from a Freezer to a Thermalright Ultra and droped ~8c under load... but a 10c drop with only lapping that impressive
 
Well done man, will be interested to see the results after a few days/week or so

just a noob question.. what's lapping?

Thats when you use sand paper and make your processor and CPU cooler really really really smooth on the contact surfaces so the heat transfers better.

cool, i never though it would make more than 1deg difference. i will seriously consider this on a future build.

how is lillia these days, lol

That's great speed for a Q6600. Hopefully you can get those temperatures down a little bit. Better for the long term.

nice!!!
 
next time post pictures

Skittle, unfortunately I don't own a quality digital camera.  I can say however, that both are shiny smooth.  What was surprising was the ammount of sandpaper I needed! You see all this copper coming off and think "this is going to be easier than I thought" but when you look at the IHS and heatsink there are still many visible grooves and scratches.
 
As a note for anyone looking to lap their Arctic Freezer 7 Pro (or perhaps any LGA775 heatsink) the plastic pin connectors and mounting bracket prevented me from using a table to lap, they simply got in the way!  So I looked all over my house for a flat, hard surface which I could tape some sandpaper to.  Well, it turned out my hero was a box of Cascase dish soap!!
 

 
For the CPU, I taped some sandpaper to a cutting board I had lying around and started grinding,

Well after reading this post at 6 this morning, i picked up some sandpaper at work today and lapped my Arctic Freezer 7 Pro, i did not touch the cpu, that sounds too scary, especially since my cpu is only a week old. Well i spent about an hour on this project. And to the guy that had trouble with the plastic clips, i very carefully took my clips of that "x" bracket and it worked just fine on the table. Well here are my screenshots with the results.
This is idle before lapping

 
This is under stress before lapping
 

 
This is idle after lapping
 

 
This is stress after lapping
 

 
Notice there was a nice change after only lapping the heatsink. There was a 4c drop for cpu temp and a couple c drop on each core. I am very happy with the results. I used the guid listed at the beginning of this thread to do it if anyone cares.

mnymn3, I'm glad to see that the result have inspired someone else to give it a try!  Your seeing a decent drop already, but why not go further?
 
The CPU was much easier to lap for me than the Freezer was.  Plus, right now you have a shiny and flat Freezer 7, and a convex Q6600!  By lapping 1 and not the other, you may have achieved a temp drop, but now you have 2 uneven surfaces.  I did some reading and learned that since move CPUs are convex, most heatsinks are made slightly concave to cope.  So your probably getting really good contact in the middle of your CPU, but the edges are full of gaps!
 
Only after 30-40 minutes of lapping my Q6600 did the top layers of the corners of the IHS start to fade.  I would reccomend that you push it just a little further and get 2 flat surfaces making as much touching surface areas as possible.

Just lapped my 6400+BE and my Rosewill 92 cooler.  Thanks for the info by the way.  I have a 9850 on the way and hope it works well for it.  Wal-mart in South Beloit IL had all the sand paper up to 2000 grit, It was 9:00pm when I read your post, all auto shops were closed so went to wally world, cost me $14.00   Idle temps are only a couple of degrees lower, have not tried to stress it yet.  I ll let you guys know.

So I'm an idiot.  Ive reading all these forum posts about peoples temps and wondering: I have great airflow and my room is not that hot, and my CPU fan is blowing heat right out the exhaust fan, why are my temps so hot?  Then I saw this:
 

 
I have the Freezer 7 backwards!!!  Its blowing the hot air from the CPU right back into the case and not out the back!!  Now if I have to reset the damn thing, which i almost broke the clips reseating it last time.  Man that sucks.  The reason I had it in its current config (i.e. WRONG) was that the reviews I saw on Newegg etc. said to make sure the fan faces the back of the case.  
 
Moral of the story.. RTFM!!!! (Read the f**king manual)

Ok so I finally got all this straightened out.  Reseated, reapplied AS5.  So Far, so good.
 
Idle:

 
Load:

 

Ive heard that using soap is a bad idea.  Anyone wanna weigh in on that?  Im thinking bout lapping my AC Freezer64 Pro.  I want 2.9Ghz so bad, lol

 
The soap made it so much easier! In fact, right after i added soap onto the heatsink was when I got the smoothest and even laps.

Water can be used as well. Lapped my QX6700 and it came out well. Didn't have the patience to do a shiny finish as I'd be covering it with a heatsink as well.  
Got about 7c drop on idle and 11on load which was pretty impressive.  
After 6 months now of burn in my processor idles at approx 34c and max load is 61c. Original temps were 43c and 74c full load.  
 
One thing, make sure you're rinse off your cpu properly with water ( distilled preferably) as the filings can cause your cpu to short circuit. It's perfectly ok to put your cpu into a glass of water and leave it for 20 mins or so. Just make sure to dry it properly later on either by air cooling it for a few hours or using a hairdryer to dry it off which is what I did. Afters I then cleaned it again with thermal cleaner and applied paste as normal.

I dunno.  I still don't think lapping will do impressive difference, at least for me.  If your not going to have cool air, and great airflow, the lapping or quality of thermal grease isn't going to do anything.  If you think about it, the coolant your using is air.  If you don't have it, or can not flow that air through the case effectively, then your going to have hot readings regardless of what you do.

I know I'm not OC'ing my Q6600 to 3ghz, but 2.850, which is only 150mhz difference.  I'm getting lower idle temps because of perhaps 3 reasons.

1.) Speed Step - reducing the voltage and speed when not in use. (2.850 ghz is reduced to 1.896 ghz when not under load)
2.) HS - I use a tuniq which can displace more heat then stock or smaller type HS
3.) Airflow - I know my airflow is great simply because of the amount of dust I get in my PC case.  . o O (one con against good/great airflow)

Now my CPU/HS are non-lapped.  I've made a thread not long ago:

My Q6600 upgrade

If your read through my thread, you will see that other said their setup was running cooler, which was linked to ambient temps and airflow.

So I hope this helps you understand perhaps things that are being over looked in trying to reduce heat, but get that extra kick when needed, which I am referring to speedstep.