Read about Gigabyte's i-RAM (Affordable Solid State Storage)
It's a really great idea, and when the new version comes out soon you'll be able to use up to 8 GB just like another HD in your PC. I'm only starting to think about possible ways to use this:
- use it for the Windows swap file
- use it as cache for image and video editing tools
I bet you'll come up with more ideas!