Fujiflyer,
http://www.drix.be/types.htm describes different memory types. Flash (which was originally a trade name) is a type of EEPROM, and it's that which is used in USB memory sticks and the like. The site also explains why some types of memory are faster than others.
Ausatco, this site agrees on FAT32:
http://www.tek-tips.com/gfaqs.cfm/pid/96/fid/3876,but I reckon if you're worried about a small difference in swap-file speed you need more RAM...