I've found a few links that could start you down the right path, BUT make sure you've got anything important backed up from your device first.
Also consider the transfer speed of your flash drive. Perhaps benchmark it, then try and borrow the fastest SD card from a friend, benchmark that. Whichever is fast, go for that.
You'll shorten the life of your SD card, you may find USB flash devices are too slow, the extra "RAM" available actually slows your device down in some circumstances etc etc, but it should be a good learning experience.
Relevant links:
http://zerocredibility.wordpress.com/2009/08/24/why-android-swap-doesnt-make-sense/
http://forum.xda-developers.com/showthread.php?t=1659231
http://forum.xda-developers.com/showthread.php?t=1945254
The last two links are for other Android devices, but should give you a grounding in the topic.
I'd also consider:
a)
ZDBox or similar apps to free RAM (again, some argue that Android's built in memory management makes task killers redundant, but it won't harm to see if it help). See
https://droidboxforums.com/threads/tweaking-apps.102/ for this app and...
b)
https://droidboxforums.com/threads/startup-manager-free.86/ for StartUp Manager free. Check which apps are being automatically loaded each boot up. If you're certain you never use them, and they're on the user tab, try disabling them. Any others, make sure you're happy with a factory reset procedure if the app NOT being loaded at boot up causes problems.
