[d] enclosed in brackets chaotic perfectionist for hire

So you've all heard of del.icio.us, right? I did too, and signed up for an account about 18 months ago... and let it just sit there. At the time, it didn't pull me in, but that was then.

For some reason, I decided to give it another try (probably because of Sean) about a week or so ago, and now I'm plowing through my 1900+ bookmarks to find the gems and weed out the garbage. It would be nice to be able to tag multiple links with the same tags (not just rename them). Of course, I really like the FireFox extensions and the ability to work with the bookmarks in the sidebar.

This isn't my first foray into social bookmarking (and won't be my last): I used Simpy for a while, but then stopped for some reason. Looking at it again today, it's got some cool features that I forgot about.

What do you use, and why? I know del.icio.us and Simpy and RawSugar, but have only used the first two. Looking at it, there may be another signup in the near future...