The official site has the Episode III poster announcement, and as you might have guessed, it's for sale at Starwarsshop.com.
From the official site:
Episode III Release Poster March 08, 2005
Last year, moviegoers were given a glimpse of Anakin Skywalker's future, as the specter of Darth Vader loomed within the folds of his flowing Jedi cloak in the teaser poster. The theatrical release poster is now on its way to movie theaters. The new one-sheet is illustrated by Drew Struzan, continuing a tradition begun with the Special Edition release of the Star Wars trilogy in 1997. This new poster places Anakin within the larger framework of the Episode III storyline, with the main cast of characters -- Obi-Wan Kenobi, Padm? Amidala, Darth Sidious, and the dark helmet of Darth Vader -- featured prominently.
Thanks to David English III for the first tip. And also to Ryan and Lord Andrew.
Rebelscum Breast Cancer Awareness Charity Patch Posted By Philip on November 25, 2014: Thanks to everybody that ordered patches. I sent a check for $1,600.00 to the National Breast Cancer Foundation on Monday. While it's not as much as I hoped for, it's still very much appreciated. They will remain for sale in the store for anybody that still wishes to purchase them. Details after the jump.