I gained 10 GB of free space within about 5 seconds this morning...

Raymond and I were venting this morning about not having enough disk space on our laptops (3 GB free for me this morning), and he clued me in to a feature in Windows Vista you can turn off to help free a lot of space - System Restore Points.  System Restore Points allow you to "roll back" the system files on your computer to an earlier point in time.  I've never thought of using this feature.  I've never wished I had this feature.  So I decided to disable it.

To get there, right-click on your Computer menu item from the Start menu and choose Properties.  Then, choose the "System Protection" task from the left-hand menu.  After your computer's gears grind for a few minutes, your system drive will show up in the list of disks where restore points can be enabled/disabled. 

In my case, system protection was enabled on the C drive, and I had about 3 GB of free space:

After disabling restore points on drive C, my free space went to 13 GB.  That's a 10 GB difference in a matter of seconds:

Depending on your perceived need for system restore points, you may want to disable them to gain back more space.  If you're pretty cautious on teh Internets and know how to operate a computer, you can probably get away with this.