Agreed. I operate under the presumption that you have access to multiple machines in several time zones like me... :-) Actually, more to the point, one thing I would almost certainly put on my USB key is a fully functional operating browser like Firefox. I plug in the key, use my browser (with all of my personized settings) and never really worry about the cache since I can put it on the fob or disable caching entirely. One other option, and a good one if you have access to boot a machine, is to put a small Linux Distro on your USB key, make it bootable, and then you operate entirely on your own personal OS. Of course, if you are pulling that information down through a proxy server or some other untrusted place, then do this (which I really didn't make clear): compress all your files into one file, encrypt it, and attach this encrypted file to a draft email document - or send it to yourself so it's in your inbox.

Thanks - nice to make myself visible after reading for several weeks. And good pickup. I sort of glossed over this. I didn't intend for anyone to put those images directly into an email document that has the potential of being cached.

Personally, I go with both the bootable Linux as well as carrying around my own Firefox environment.
Portable Firefox is a good place to start. I recommend Damn Small Linux or
Slax, but there are many fine Live Linux Distros that will work great depending on the size of your key.

Edit: One other thing... I'm not sure that storing files on Google or Yahoo (especially encrypted ones) constitutes a larger security breach than an unencrypted USB key. They are easy to lose, break or drown and the web option keeps your secure data behind the login of a secured email system. I've operated mine for years without any problems whatsoever and they are there even should my USB key not make it out alive. :-)