http://members.optushome.com.au/vitu/hs/ocrest.jpg
Its based on that belt buckle. As for info, from what I gather the buckle is based on an old American Indian symbol. Something to do with the elements, wind/fire/earth/water and all that crap. I seem to recall some stuff about it in the creed quest, but I didn't really pay attention to that, as it seemed like a bit of a cop out. For a big-ish image of it:
http://members.optushome.com.au/bfairfax/c...crest_black.jpg
Unless you were talking about the short lived first Creed crest, which was some stupid design Dan Tremonti came up with, which appeared on a few t-shirts but was dropped.