I had fun with the online image generator activity. I think the Custom Sign generator would be most applicable for a computer class. The comic strip generator can be good, too, as it can be used for history lesson, or any subject really. It was easy to get lost in all the links, really, and to lose focus. Any activity of this sort given to students would need to be very precise in instructions, and I would need to be sure to keep kids on task, as some would spend too much time looking around. I sure did! I can see this being more useful in libraries and at the elementary and middle school levels, but high school classes could have fun with it too and learn something, depending on how lesson was structured.
The link I used for the image below that I created is http://www.comicstripgenerator.com/maker.asp.