I have a distaste for lots of toolbars; I like my browser simple. However, for those it suits, Yahoo's toolbar is now available for Mozilla Firefox if you're running Windows (OS X and Linux versions are in the works.) Earth times have an article, of which the last two paragraphs are most interesting:
While a lot of individual users are expected to be happy with this freebie, analysts warn corporates against migrating from MS’ Internet Explorer to Firefox.

They point out that FireFox’s growth is so far ‘unsustainable’. Its features were designed more for individual users. Corporates need to think twice before using Firefox because it has repeatedly been targeted by worms and viruses. That is the reason why it cannot compete with the Internet Explorer. The analysts expect that Microsoft may consider retaliating with an upgrade, but that may depend on its upgrade plans for Windows besides the development of the much awaited Longhorn operating system.
What? "Corporates need to think twice before using Firefox because it has repeatedly been targeted by worms and viruses. That is the reason why it cannot compete with the Internet Explorer." Oh OK, so Firefox is always being targeted by worms and viruses, which means it cannot compete with the far more robust Internet Explorer. Hang on... who were these analysts? Did they work for Microsoft or something? There are valid reasons why IE may remain the browser of choice (it being bundled with windows would be the biggest winner for it, in my book) but these analysts seem a bit off the mark.