Addthis.com - Now has a add-on for Firefox; It however only shares with one service that I've added a Stickr to so far.

SecondBrain.com - Social bookmarking site. Decent bookmarklet. Can organize websites into collections with an automatic screenshot.

bagtheweb - a social bookmarking website where a "bag" is filled with associated links. links look attractive. not a lot of activity.

Linkpager allows one to group links into different categories and share them. Screenshots of the webpages can be captured automatically.

Oi quero link para mi trabalhar