Alright.
Google: Search, email, maps, calendar, news, groups, blogs, pics (picasa), video, dating (I only fell for their joke for a few minutes....). I'd say i'm hooked on free, non-annoying add supported software. The wave of the future? or an idea that will sputter out?
Firefox: tabs are handy, I've got 6 open right now, the find on page feature is GREAT. And what's sealed the deal for my is this, I just learned how to set focus to the location edit box via keyboard shortcut: ALT-D. I like IE's F4 better, because i've gotten used to it, but alt-d won't take long to get used to.
Also switching between tabs: CTRL-TAB or CTRL-[1-9] might be nice if they numbered the tabs for you...