Toys N Joys has created a whole series of really neat Sonic themed posters and wall scrolls. You can buy them online in Spring 2009 at www.toysnjoys.com !
Here are 2 Riders themed posters, the first with a detailed background and other riders, and the second one, unusually enough, with ONLY Jet the Hawk. Despite being a rival (rather than a nemisis) this may be the only item he appears on solo. It's great if you're a Jet fan! It also shows they're not afraid to reach out and do other characters.

BUT BEWARE of Toys N Joys! They currently have a bunch of bad 1-star reviews, so be sure to check their reviews FIRST. 

Three more non-Sonic wall scrolls. Knuckles looks all right on his red and steelplate background, though if it doesn't go with your room, you're out of luck. Shadow's gun poster is really rather menacing, which is curious because who really wants an angry scroll aiming a gun at them while they sleep. The horizontal Shadow one looks like a scene from his game, as he crouches in a city at twilight. He looks slightly perplexed here, which is another unusual move, but again, it's NOT more of the 'same old thing' with any of these scrolls!

• CG Sonic rivals CG Sonic rivals
• Sonic Rush Adventure Sonic Rush Adventure
• CG Sonic jumping CG Sonic jumping
• Sonic & Amy Sonic & Amy
• CG Sonic CG Sonic
• Sonic Adventure 1 Sonic Adventure 1
•  

3 scrolls using CG art from one of the games. The first obviously lends its running/pointing Sonic to the last one. All use some speed-lines and blurring to give them a sense of action coming toward the viewer. Knuckles and Shadow seem a bit oddly dropped in on the first one, but any of them are a pretty decent decoration for a Sonic room.

Then there is possibly the first item to have Marine on it? This poster has the whole cast of Sonic Rush Adventure (Even Capt. Whisker & Johnny!) If you're a Rush Advtr. fan, you can't pass up this poster. The other has just Sonic & Amy in a Sonic X style, but without the X logo. The last poster is obviously from Sonic Adventure 1, so it's likely a re-release or VERY similar to an earlier work.