Most utilitarian Firefox plugin.

So I just ran accross an incredible firefox plugin for keeping your bookmarks synced accross machines and OS's. I in particular have 5 machines running a total of 7 different OSs. Suffice it to say, I've never kept my bookmarks organized until now. Foxmarks allows me ot keep my bookmarks on their server, and then automatically populate my firefox bookmarks menu.

https://addons.mozilla.org/en-US/firefox/addon/2410

Check it out.