This is the Star Trek TNG Ten Forward Door Cover available from ThinkGeek. It's a 38" x 84" piece of printed polyester with elastic corners (like a fitted bed sheet) that fits over a standard interior door to make it sight like the entrance to the Ten Forward bar in Star Trek: The Next Generation. And,as you can see in the picture above, it doesn't really deal that well with door handles, or so you're probably going to need to gash a hole if you want your friends to remove the new entrance to your rumpus room seriously (personally I went with a beaded curtain that glows under blacklight and maintain zero regrets but tons of trippy swingers parties). support going for a closeup.
Source: geekologie.com