I've started using Diigo. I haven't quite let go of Delicious but that's one of the good things about Diigo. It allows me to automatically export my bookmarks to Delicious so I don't need to use that service directly anymore. It lets me filter my tags and works directly with Blogger so I don't have to do a tortuous backdoor route to get my bookmarks into my blog. And the toolbar - I have to say that although it takes up more space than the the Delicious buttons... it's fab! You can highlight and make comments on pages and it interacts easily with some of the main social networking sites such as Twitter or Facebook. It does the things you didn't realise you wanted Delicious to do, but now you've got a taste for those features, you don't really want to go back...
