I am probably the only person out of the loop on this, but I have been frustrated that there was not a spell-checker on the BGE Forum.
On a different forum where I participate (B&B Shaving Forum), I was directed to download a product called "ieSpell" at www.ieSpell.com
It is free for personal use and seems to work well here and other places. You select the text you want to check, right click and select spell check.
It even allows you to develop personal spelling lists, so everything from BGE to EVOO checks as okay.