There are a few
SEO-related blogs out there that will accept articles. The ones that I can think of off the top of my head are Search Engine Guide and Search Engine Journal and (ahem, my own blog), it's in my signature below.
I would be careful about duplicate content, though. If you're going to get your article on another site I would make sure that it's unique--if you submit too many of the same article then anything more than the first article will most likely be considered duplicate--and won't really "count" as a link back to your site (if that's what you're after).