Microsoft has really jumped into the whole Web 2.0 thing with both feet this week with the launch of a new social bookmarking service, currently in beta, called Tagspace.  The idea is to create a central, massive set of bookmarks.  Users can add links to the service, and with each link toss in a few descriptive "tags" to help classify and sort what the link is about, in theory letting you group it with similar links, making it easier to find information.  The service has two views, a public one and a private one.  The public side of things behaves much like you'd expect other Web 2.0 social tagging sites to, giving you a high-level view of the overall most popular links tracked by the community. 

The private side is just for your own links, and it has the potential to be very useful in sorting and retrieving personal information.  How often do you bookmark a page, thinking you'll come back to it later, but when later comes, you can't remember which link you were looking at, but you remember it was about purple bunnies.  With Tagspace, you'd look for the "purple bunnies" tag and find your link.  Very handy potentially.

Here's a bit of description from Microsoft's info page on the new service:

"If you’re unfamiliar with the term "social bookmarking," you can think of Tagspace as a gigantic "Favorites folder" on the Web, which frees you from having to import and export your favorites from browser to browser and computer to computer. It also allows you to organize your links in a more intuitive way than you can just by using the bookmarking tools available in your browser. "

Check it out if you've got some time.  The link below will take you to the overview page describing the program in greater detail.  You can link to the service itself from there.  For the personal tags portion, you will need a Windows Live account.