Virtual memory - if you bump it up to 1GB - will speed up your computer!
However, I recommend that you go purchase a 512MB memory stick. This will DRASTICALLY increase your speed. We get our memory from http://www.northalabamacomputers.com/
- you can call and talk to Brett, and he can hook you up with the right memory for your machine. They ship via UPS. Their prices are definitely competitive.
Your virtual memory is a huge file on the hard drive that Windows uses to store currently-unused items from RAM; and it swaps them out in the RAM as needed. Virtual memory IS slower than actual RAM, but increasing it will still have an effect on your machine's speed.