I seem to lose mine after about 3 months of usage. I do have one that's held together with tape and has bits of casing missing from it that I've had for about years but I havent used it in ages. It's only a 1GB and its veeeeery slow. Slow as in 2MB/s reads and 700KB/s writes.

I recently lost a very nice Transcend Jetflash 4GB. I'd written a piece of coursework in the morning, saved it to the drive and then I went and had lunch. I forgot it in the computer and some motherfudgeer 'borrowed' it complete with work. I backup my flash drive nightly but, of course, the work hadn't been backed up yet. Gone. I checked back on that computer for temp files and the like but they're all removed at logoff. I had to redo it.