I came across an amazing tool connected to the social bookmarking tool del.icio.us. It's called del.icio.us direc.tor. It is rather amazing. Here's a screenshot of what it looks like for me:

Basically, it takes your tags, and organizes the bookmarks according to their tags. This is very, very cool.

There are details on how this works (via XML, XSLT and Javascript). It only works in Firefox and IE, it doesn't work in Safari (here is what the author of this tool has to say about Safari.)

It makes me want to bookmark and tag just about everything I come across, though!