For all who are interested in having spell-check capability, I discovered today that the latest version of Google Toolbar includes a built-in spell-checker, which will work with any web site you visit.
Google Toolbar is free, and has several other useful features that many of you might appreciate, such as a word translator (convert English to other languages and vice versa), pop-up blocker (which is already built into Mozilla/Firefox and the newest version of Internet Explorer, but this is useful if you're running an older browser version for some reason), and some other nifty features. The spell-checker alone makes it worth the download.
Mozilla/Firefox version:
http://toolbar.google.com/firefox/
MS Internet Explorer version:
http://toolbar.google.com/index_2
Edit:
I've been searching all over the web trying to find a web browser spell-checker that's freeware (not shareware or demoware) and so far Google Toolbar is the only one I've found. I'm sure there are several good shareware web browser spell-checkers, but I didn't want something that was going to nag me about buying it or sending in a donation, or worse yet, annoy me with advertisements.