i sometimes use it for finding new stuff to read, basically just by searching the community library for whatever tag i'm looking for, the searching within that list for other tags if i want to refine the list. But also, you can have friends and groups within diigo and create your own little network or whatever, so you can send each other links and see each others bookmarks or what have you. i don't actually use that feature, but the mister does (for work), and apparently it's v useful because you can make notes and add highlight on the pages you bookmark, and when you share the bookmarks the people you share them with can see your notes and highlights. i can see how that be cool when recc'ing stories to friends, though. i just haven't done it!