...If you have really sensitive information, check out IronKey (
www.ironkey.com). It's a FIPS certified USB flashdrive that will soon be available in an 8 GB version (in another 2 weeks or so). After 10 unsuccessful password attempts, it will destroy the data. If someone tries to pry it open, it will physically destroy the chip. It's a very secure flash drive for those who really, really need to protect their data.