Comics are an effective way of conveying ideas and messages, retelling stories etc.
There are heaps of free online comic creators -some will allow you to upload your own images, others provide a range of their own. Most are two dimensional - others allow you to build scenes into movies. Below are some useful links.
Comic Site Links

Comic Strip examples

The powerpoint is the work of S. Hendy and provides information about the advantages of many of the Comic Creators listed above. There's plenty out there - just have a look and decide what best meets your activity's needs.

Xtranormal example