If memory leaks (programs not releasing memory once they are done using it) or other memory issues are a common problem of yours, then a handy utility for you is RAM Idle LE.

RAM Idle runs in the background and, well, from the editor’s review:

The program icon sits in the desktop tray and displays the amount of memory your PC has available at any given time.If you know you’ll need a certain amount, you can specify that amount; otherwise, you can let the program run automatically to balance memory needs vs. memory available.

While I’m not exactly sure how this is accomplished, one key feature is the ability to assign memory to a specific application so you know it has the memory available it requires (for games perhaps).

Personally, these kind of things are not up my alley, but I would be interested to see how effective it is. If anyone uses this program, please post a comment.