iStarin.com is a web-based photo editor that allows its users to create funny movie posters with their own photos. In general, the site is easy to use and does what it claims - （make you）"Become the Super Stars on Blockbuster movie posters".
The magical trick of this website is actually the face detection technology. As a photo is uploaded, the face will be automatically detected and matched to the templates. (It's like the face detection function on many digital camera.) I suppose the posters must have been edited beforehand to locate the position of eyes, mouth etc.
A good thing about this technology is that it saves users from the trouble of sizing, positioning and color matching. However, this technology has rather strict rules over the photos submitted. To achieve the best result, it would have to be a front-face shot, with minimum amount of hair covering the face.
One thing I like is that (apart of being a free site and requiring no registration or installation), iStarin.com allows its users to save high resolution posters onto their computers or share them to other destinations (Twitter, Fackbook etc.). So it's pretty convenient to let your friends see you on these posters.