I haven't had a chance to read this whole thread and I typically don't pay alot of attention to all the curiosities people find on mars; however, this one is interesting. I believe there is a link to the NASA original. Doesn't look like a natural formation to me.
http://www.abovetopsecret.com/forum/thread369488/pg1
http://www.abovetopsecret.com/forum/thread369488/pg1