Similar extensions exist for Chrome, but they require running a server in the background since Chrome doesn't let them execute external processes.
Vimperator and its recent fork Pentadactyl do this for Firefox, there's similar (though when I looked into it, less advanced) add-ons for Chrome/ium too, I think the one I tried was called Vimium.
I was worried using such an invasive add-on would trip me up with Firefox's new rapid release schedule, particularly as I jumped to Pentadactyl because it supported version 4 first/better) but I'm up to Firefox 6 with no problems as yet.