I'm trying out the Spelling Checker plug-in for WordPress from coldforged.org. It seems to work nicely and I like the interface. According to the author of the plug-in, it piggy backs off of the open source package Speller Pages for the core functionality. Open Source is sooooo very cool. This is a great example of it literally building on itself and becoming greater than the sum of its parts. One note, the default install of the plug-in didn't work for me with out changing the "Aspell language" from "en_US" to "en". Before I made that change I got and error that listed the aspell command it was trying to run followed by the string "Error: X?w". Once I made changed the language option it kicked up just fine. By default, the plug-in only adds a spell check button to the place where you create new entries. Directions are included on the main scripts page for how to added the spell check button to the comments area as well. I've done this as well since I'm bad at spelling and want to not make a fool out of myself when adding comments.