I know of HDD utilities that can recover data that has been deleted from the recycle bin. Does zero filling a hard disk drive really make all data on it totally unrecoverable?

No.
The more times you do this the harder it is to retrieve the data.

If you do this a couple of times, you should be relatively safe.
However, the Gov't if it really wants to can do amazing things to get at the data.

Most ordinary hackers will not get past the 0 wiping.

Run the zero filling about 10 times. If you are really paranoid, BURN the drive and buy a new one.

If you really need to make the data unrecoverable then get a program called Darik's Boot and Nuke. It's free. Just be careful with it... I never boot up DBAN on a PC unless I want the data on EVERY DRIVE permanently deleted.

The data may still be accessible with very high end tools (think of Mission Impossible 3), but will a single zero fill make the data inaccessable via most data recovery software in the market today?

What are you trying to hide anyway?

Yes. It will be safe from normal recovery tools.

With the data density on modern disks it's probably safe from anyone; but overwrite multiple times with 0, 255 and random values if you're paranoid. Took about ten minutes to write a C program to do that.

Take a hammer to the printed circuit on the bottom of the drive.

No one will ever find it cost effective to recover the data.

Well considering the government spends millions on political campaign advertising, what is another couple of thousand for some data they really want?

Unless you robbed a bank and kept your check list, get away plans on the disk.

But they would likely see you viewed this page as they would contact THG for people logging in and out of the board.

There's not much you can do that doesn't track you in some way or another.

Absolute best way is zero fill several times and deep six it somewhere... but zero filling takes a long friggin time.

^Thats why you use proxys and Linux

what you dpo is you unscrew wthe case off the disk, then you get an industrial electomagnet, wave it over it a few time and no-one will ever get any data back...

if u want ur data delete there is only one way to ensure its gone and completely unrecoverible. i served in the military and know first hand about this. you need the disk destroyed and when i say destroyed i have some specifics...first you need a super strong magnet or electomagnet....you need to place the magnet physically on all disks...think thats enough...well its not even that can be undone with the right tools. after your done demagnitzing the platters you need to either sand/sandblast them down at least a half milimeter and or use a welder on every square inch warping the disk and melting the platters. and of course if ur doing this to military/ govertment spec (for classified material)before you do any of what i said you have to reformat refill the drive entirely with "filler" data at least 15 times....think i am joking....i am not laughing. even than its possible to recover minute amounts of data. but its the best way there is...cousre down side is ur hdd is toast. all depends how bad u want to get rid of the data.

Send it to the sun, if the heat doesn't fix it up, gravity will. And I don't think even the military/government will bother trying to retrieve it from there.