What's the easiest way to create a double exposure (you know, two photos layered on top of each other in an artful manner) without winding on a roll of 35mm or spending too long in Photoshop? New British app Dubble does it for you, pairing your creation with a random user's photo from around the world.
Either import a photo already taken, or snap a photo using the Dubble app, and within seconds it will collide with another Dubble user's photo and create an arty double exposure snap. Share it on your social networking sites (Facebook, Twitter, and Flickr support are baked-in); download it to your camera roll (which you can then upload from to social networking profiles the app doesn't support just yet, such as Instagram), or just leave it on your Dubble profile for all to admire -- it's up to you.
The photos this app produces are just amazing -- I shoot a lot of film photography, so have been blown away with how close the results are to the real thing. It's little wonder this app has come from the ex-MD of Lomography UK, then.