Good idea. Although, I wonder about the reliability of flash media.
A lot of laptops use flash drives versus disk drives. Means less power but how does the failure rate compare?
Current Apple laptops are pretty much all SSD. Checking the lineup, it looks like only the bottom end MacBook Pro still has a hard drive (500gb, 5400 rpm). The other MacBook Pros and the two MacBook Air models all have flash storage.
Once you have adequate RAM on a machine, the best way to boost its subjective performance is to substitute an SSD for a hard drive. Next time you visit an Apple Store, bring a stopwatch and time the various models rebooting.