Completely agree - been using this for a year now on 4 PCs and it is fantastic.

gglave - I tried really hard to like Google Bookmarks but I just couldn't. I like the idea but compared with Foxmarks it is just really cumbersome.

Foxmarks, combined with the Firefox 3 address bar, works incredibly well. I don't even use folders now for the most part, just star anything I'm interested in, occasionally add a couple of descriptive keywords, and just type into the address bar to find them, on any of the PCs that Foxmarks is synced with.