I've seen these comic strip builders before, but this is the first one with a decent collection of objects, characters and a really easy to use interface. Really fun tools to mess around with.
Found on the always entertaining chrisdiclerico.com blog.
Edit: If you need some ideas for how to create a strip click here.
It really is a lot of fun. The only thing missing is being able to make your own objects and characters and change font/font size.
How the heck do you comment on a cartoon there?
Here's my first strip... http://www.thirdframestudios.com/adgame/stripgen/viewEng.php?id=16691
Look out Gary Larson -- there's a new kid in town.