http://www.posteroffensive.com/
Click "ARCHIVES." Flash prevents a direct link.
Tons of high res, downloadable posters, some really excellent work as well as utter retardation.
Wow, some of those are very nice! Others, eh... their leftwing, anti- :mullet: attitude is a bit stronger than I think we are going for with PosterGASM.
Still, an excellent find.
Case in point:
(http://img524.imageshack.us/img524/6668/kellymunsonia5.png)
(http://img504.imageshack.us/img504/8103/craigduffneyzs7.png)