There are now high-capacity very fast USB "thumb" drives; the models with "speed-boost" compatible on their specs.
Maybe the next version can take advantage of this for database files or "swap" file space?
I have a 4 gig myself and I know they have 8 gig units, which should be more than enough space.
...and they are much faster than your typical hard drive and CHEAP; $49 for 4 gig @ staples and I'm sure much cheaper on the web.
Just make sure it is "speed-boost" rated and it needs a USB 2.0 port also...