As everyone said, keep it on the SSD and keep it small. Some ppl worry about wearing out their drive with pagefile on their SSD and I would not worry about it since you will probably be replacing this drive long before the expected NAND wear-out.
I run 4GB of memory and I have my pagefile on my SSD set at 1.5GB, and even set at 1GB is plenty. There are some programs that can be very picky about having a pagefile enabled. I ran my system without a pagefile for a very long time until i started having problems with a few applications and 1 game. Civ5 would constantly boot me to desktop even though i was not running any programs in the background until I set my pagefile to a small level.
8Gb of RAM would be nice but, this amount of DDR2 is so damn expensive versus DDR3. Might as well save that money toward a new board/BD chip if they ever come out