as indicated in a recent post in neowin, although these "hack" will speed up firefox a little, it has side effects, some websites may not generate properly and the paint delay hurt servers.
want to speed up firefox? wait for version 1.1.
hotmail is not slow now, but there are too much crap ads in hotmail. I like gmail but it bothers me that it is still beta and may never hit publick, which means it could dispear any day, although I don't think it will happen until google is broke.