Photoshop art can be very entertaining, and probably takes a bit of skill to master. The results, however, can be awesome.
Worth1000.com is a web site which holds various contests photoshop enthusiasts. One can send in entries of animals made into vehicles, of movies or celebrities mashed together. I'm impressed at the level of skill the entries display; it makes me want to try it out myself.
Try going to worth1000.com and surf through myriad galleries of photoshop art. The most entertaining ones for me are:
Mate a Movie (12 galleries) - Want to see Jimmy Neutron in the Matrix? Now you can!
Movievision (5 galleries) - Merging TV and movies. Similar to Mate a Movie.
Animal Crossbreeds (1 gallery) - Doctor Dolittle would have fits.
Bad Ads (3 galleries) - Of course, a lot of these are based on American ads, but still fun to view. Warning, though: some of the ads are rather gross, so you may want to pass on them.
And these are just some of the things one will find on the site. There are a lot.