After struggling to read a couple posts due to run on sentences, spelling, etc, I decided to post a couple little tricks I use to try make sure my posts are understandable even though I don't type well, and am a touch dyslexic.
My first line of defense against atrocious spelling is a little editor for Windows called tinyspell: TinySpell - Free software downloads and software reviews - CNET Download.com
For Linux I use Firefox with: https://addons.mozilla.org/en-US/firefox/addon/9207
And finally, a tip: Sometimes I'll open my word processor (mine happens to be Open Office. You could just as easily use Word) and type my post there. This will highlight spelling, some run on sentences and makes me slow down and review.
None of this will help much with grammar, but it will at least help enough to clean up a post a bit, so it won't get ignored.