The Verbatim Store'n'Go Netbook USB drive is so small that you can plug it into your netbook and just leave it in there. So this is a dead easy way to expand the onboard storage - especially for those first or second generation netbooks with very limited and usually very slow internal flash/SSD storage.
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips