I'm posting this entry from within Flock, a new browser based on Mozilla, the codebase which underlies Firefox. You might think the world needs a new browser like it needs a hole in the head, and I more or less agree with you, but Flock has some really cool features:

All in all, very impressive. I hope that some of these features (especially the social bookmarking integration) make their way over to Firefox, but I'll be keeping an eye on Flock's progress.