Oh, don't get me started! .... "Noone" for no one (yes, it's two words too); and the there, they're, their debacle. Dose for does; its and it's; two, to and too and the lack of apostrophes drives me bonkers! Is it laziness, lack of education or a hangover from texting on cell phones? I don't know, but if I can't make out what you're trying to say (oh, there's another one - your and you're) I won't read or respond to your thread.

As for a spellchecker, for Internet Explorer there's iespell - http://www.iespell.com