I've been saying for years that I need such a contraption on my car!! You bikers have all the fun!
del.icio.us has plugins for IE, Firefox, and there is a less useful third-party plugin for Safari which make it easy to "sync" your bookmarks across computers, so I use that for my browser synchronization.
TrueCrypt keeps my really important data (passwords, resume, other sensitive personally identifiable info) safe and secure on my USB drive.
My USB stick on my keychain holds a copy of TrueCrypt to boot from directly when you plug it into a USB port (you need admin authority on the computer you're using to use this feature though), and then some other miscellaneous documents I wouldn't want to lose but aren't sensitive sit on my USB stick in generic folders.
And lastly, my iPod holds a copy of all of the music I care to not lose. (My wife and I also have a 750GB backup drive attached to our iMac at home to keep all of our media files, like photos and video, backed up)
Everything else is either done "in the cloud" online for us, or is proprietary or sensitive data that shouldn't be getting moved off of the primary computer it is on anyway.
Because people should just stop touching the monkeys. They've got problems enough as it is!
They are relatively good but absolutely terrible. -- Alan Kay, commenting on Apollos