Not that anyone really needs a spell checker for Forum work, but just in case anyone is curious there is an add-on for Internet Explorer that will spell check your writing on any web page. Of course you must click on the icon to check, and if you forget to click it, your writing will go on untouched.
http://www.iespell.com/
I found it on the Windows Market Place site. http://www.windowsmarketplace.com/category.aspx?bcatid=834&tabid=1
Of course it is just a crutch and we really should take pride in writing without mistakes in the first place. I take pride in using crutches so I am not one to throw stones.