BigHugeLabs provides a great way to make posters and trading cards easily. Best of all, using the free education-specific login students won't see any advertisements. It's good for younger kids or an older kid who wants to put together a presentation fairly quickly.
"The National Science Foundation's International Science & Engineering Visualization Challenge annually recognizes individuals and organizations who produce educational graphics. There are five award categories; videos, interactive games, informational posters and graphics, illustrations, and photography. The awards recognize outstanding visualizations that can help educate students about complex topics in science. "