I just read about a program called "CleanMem" on gHacks.net, it's a little program (36kb) that reduces the amount of memory that running programs use. There are lots of programs out there that claim to do the same thing that work by filling your memory, forcing stuff to be moved out and into a file on your hard drive. This program's different, because (from what I can tell) it tells Windows to reduce the amount of total memory a program's using... so it literally changes the amount of memory a program uses, not where a program's memory is currently stored.

I've tried it, and it seems to work great, so I'd definitely recomment it :) did I mention that it's freeware? Download it here: http://www.pcwintech.com/node/145