I been using FireFox for a long time, but I am thinking about using Chrome and see if I notice any difference.
I just went to look at http://www.flock.com/ and it is no longer going to be around. Not sure why I just had a quick look.
I used to use Firefox, but now I'm using RockMelt, which is basically a slightly more streamlined version of Chrome with built-in support for Facebook and Twitter, if I'm honest.