Computer help: Is there such a bookmarking service for me?

Another option

Another option, which isn't exactly what you're looking for, but might be sort of an alternative approach to solving the problem: Portable Firefox.

This is a version of Firefox designed to run off of a USB flash drive or even a memory card of some kind. It can do pretty much everything the regular desktop Firefox can do, but all the files it needs to run are contained on the flash drive. So your bookmarks follow you, settings, extensions, login info, the works. And since it's a flash drive, you could presumably store copies of web pages in the excess space.

There are a couple of things to be aware of. Portable Firefox is (last I checked) Windows only, so it won't do you a lot of good if you run across a Mac or Linux machine. It will be a little slower as a result of the special launcher that makes it work. Nothing too significant, but just be aware. Finally, it often lags a bit behind the official version, so if a patch is released fixing a nasty security vulnerability, it might be a couple of days or weeks before Portable Firefox is updated for this new version. So you need to keep yourself current on these things if you don't want to put yourself at risk.