First Delicious and now this? I think the best feature of Diigo are the apps for both the iPhone/iTouch and Android phones. How often have we been in a holding pattern (i.e. the doctor's office, stuck watching a train pass, etc.) and wished we had a book or something productive to do? Well, Diigo apps are the answer for students everywhere. The apps allow us to download articles and read them offline. You can also add text notes, bookmarks and even pictures all from your phone. Diigo is another great Web 2.0 tool that will make you more efficient and allow you to keep track of all those articles you need to write an 'A' paper.