LiveBinders -- Your Online 3-Ring Binder! (and haven't we all said "if only I had...")
Just started playing with this, looks cool so far -- share recommended (and previously viewed and tested) websites with students and parents. It's like your Favorites list but expanded and more detailedly (?) organized, and publicly shareable. Need to find out if each page/tab must be a website? How about PDF or...?
3rd grade Math sample: http://www.livebinders.com/play/play?id=1619