Last year I began using del.icio.us to bookmark my favorites and found it especially useful for saving and organizing bookmarks I need for my classes.
This year I've added Google Docs to my list of tools. I use it mainly to keep notes and information for my classes although I have added a packing list I can use for the seven trips I'll be making to Portland in the next four months. The main advantage of Google Docs is that I can access my work from any computer with Internet access. This would also be an excellent tool for working on group projects because the pages can be shared.