Thumbdrives are nigh on indestructable and almost impossible to loose data on. That being said, a transient EM signal or static shock on the pins could toast your data. That can be prevented by using the cap. <img src="/images/graemlins/smile.gif" alt="" /> I like a bigger cap, like the SanDisk MiniCruizers have. I usually put a wrap of electricians tape around the body to make it VERY snug, and go with it. MAYBE an xray machine could do it, a medical xray probably would.

CDs are cheaper in terms of MB/$, and are almost impossible to scramble in term of loosing thier data. Sure, a big enough EM signal could do it, as anyone who has ever microwaved an AOL CD can tell you, but pulses that big are pretty hard to find unless you are right under a really big radio antenna or in a microwave. And the former is unlikely; if you are in the latter, you have other problems.

If you want really stable long term, go hard copy with archival inks on rag paper, hermetically sealed in a nitrogen atmosphere. <img src="/images/graemlins/smile.gif" alt="" />

FOr what you are talking about, I'd say use mini-CDs. They hold 185 or 210MB, depending on the brand and style you get, and the fit in the little, inner ring area of you CD drive. Use universal formats for your documents, and any machine that SHOULD be running can read them. They also take up no room in your BOB.

For the stuff you send away, regualr CDs are much better buy.

But for day to day, USB-based flash memory trumps all the others.