At Bzzster you can send links to friends as you browse the web. It's pretty simple: when you find a page you want to recommend, click the Bzzster bookmarklet, the Bzzster "send to a friend" page appears, fill it out, hit submit, and you'll be taken back to the web page you were on.

Well, Bzzster offer widget also - you can create widget from your recommended links. I put it on a right sidebar.