One, you can use Diigo as a browser add-on very much similar to other social bookmarking sites such as Digg (sounds like eh?). But unlike Digg, Diigo lets you highlight a portion of a particular site that are of interest to you, attach a sticky note into the highlighted portion of the site, and when you return to the site, you can still your sticky notes. Sounds cool, right? It’s as if you were highlighting a book. Everything that you highlight, you can also search, access, sort and share from any PC or even on your iPhone.