I've been Diigo extensively for the last year and would highly recommend it. My favorite part of Diigo is that I can easily save highlighted text and the highlight remains when I return to the web page. It also stores the highlighted text in my Diigo account, which is handy in case the web page goes down and I need to access the information. In addition, Diigo allows me to tag my book marks and include sticky notes on web pages. Another great thing about Diigo is you can connect with friends and share each other bookmarks, highlights, and stick notes. Diigo works best in Firefox, because there is an "add-on" for it. Unfortunately, I only use Chrome now but Diigo's made up for that with a "Diigolet" that gets you most of the way there. In summary, Diigo is an invaluable tool for anyone that reads extensively on the web and wants to save and organize online content.