When I ask people how to promote my sites, they usually responds, print out a bunch of stickers and put them around on busy places in the town and especially in campus areas, anyone that have a good experience with that?
The problem with something like this is that it will be hard to tell how many people visit your site in response to the stickers. They will all be direct entry visitors. You will see a traffic rise, but it could just as well have been to TV exposure or something. Other than that, I haven't tried it myself. Depending on your target visitors it might be successful.