Windows/Mac/Linux: Freeware application Phantasmagoria adds effects to your digital photos through a slick, simple-to-use interface. The program provides an impressive range of effects and can upload the results to photo-sharing site Flickr or easily share your results over Twitter. You can snap and annotate screenshots, and take webcam photos and go straight to adding effects, similar to OS X's Photo Booth. Phantasmagoria is freeware, cross-platform, requires Java. Check out the sample page for a closer look at Phantasmagoria in action.