What should i do with these old parts?

Try selling them on craigslist or anandtech's for sale forum (you have to register and display your email address).

You could put a home server together.

You could give them to me  

In all seriousness, those parts are still very usable and should still be plenty effective for doing anything short of heavy-duty video editing or number crunching types of applications. It may not win all of the benchmarks, but it should handle pretty much any game at a reasonable framerate. If not, get yourself a newer GPU although the GTX260 is still a pretty powerful unit. I wouldn't replace those parts yet unless I was either moving way up in core count to a dual Xeon or Opteron workstation, or if I needed another machine for another purpose (such as a media center PC) and was going to repurpose this machine in that role.

If you just have the upgrade bug and want new parts, you have a few options for the older parts:

1. Sell them, either on eBay or a for sale/for trade thread in one of the other major hardware forums such as [H] or Anandtech.
2. Turn that machine into a media center PC/HTPC. It would make a nice one.
3. Turn that machine into a file/backup server. Everybody needs to be able to back up their computer(s), and having a machine in-house to back up to is a lot faster and more secure than using somebody else's machine over a slow Internet connection in "the cloud."
4. If your ISP allows, you could use it as a Web server.
5. Use it as a test machine to try out different OSes and software. Since it's not your main machine, if you screw it up, just reinstall.

Computers are handy and the list goes on.  

+1 to the windows home server option, really handy for decluttering main machine, and automated daily backups over GBe really useful, especially if there are other machines (laptops) in the house as well.

I am might be interested in this
AMD Phenom II X4 Quad 955 Core 3.2GHz Processor x4