I don't like to gush about new hardware/software when I've only hardly used it . . . . . but I'm so wowed by the half-hour I just spent with Zotero -- a free and open-source on-line service for keeping track of your files and research -- that . . . well, here goes! :)
Zotero does the one thing I've been desperately wishing for ever since I started writing research papers back in September -- it not only lets you store pdf's online of the articles you're reading (which Google Docs does a great job of), but it also allows you to keep notes on all those files and organize them fifty-million some-odd ways. There is a program they like at NYU called refworks that lets you do _almost_ all of that -- everything but have easy access to the articles themselves! . . . . Which makes me feel like a well-groomed elephant who can't find his trunk. . . Or some such animal-based metaphor. :)
Zotero, on the other hand, gives you the full package. And I suspect that Zotero's utility is far beyond the graduate research area. I'm looking forward to using it more!