Really Useful Stuff: Diigo

If you ask me, Diigo is the best thing to come out of Web 2.0. It's not a Digg-alike: the name stands for Digest of Internet Information and Other Stuff.

In short, Diigo is a social bookmarking site that comes with an optional toolbar. But: you can highlight content in webpages (the way you can highlight text in Microsoft Word or FrontPage); add comments (as sticky notes); find people who have similar interests as you (who have bookmarked similar webpages), and most importantly, the page you bookmark will be saved to Diigo's archive, so it'll never vanish even if the site returns a 404.

And that isn't even half of Diigo's features. The thing is still in its infancy (the latest is Diigo 3.0 beta), so not many people know about it. All in all, it's a great research tool.

Hop off to Diigo's website to get started or view an introductory video. Here's my Diigo profile.

For: Ground-breaking social bookmarking features
Against: Minor bugs (deleting cookies will reset some preferences to default)