I was at a meeting with some Elementary Computer teachers in my district, looking at some web-based drawing programs, and I mentioned the "Still Life" Painter on the US National Gallery of Art site. If you haven't seen it, it is worth a visit.
While it can be a little slow to load (depending on your connection), it's great fun. Students can view a "typical" still life composition and then take a turn creating their own, using the various elements provided. You can choose the table, the drape, the background, the fruit, the bowls and additional elements. Then you can add a "paint" effect to personalize your creation. The interface allows the student to create 8 different versions and hold them in "frames" along the right side of the screen (activated by the "look" button.)
From the site:
[Students] can explore spatial arrangement, perspective, proportion, and balance while creating engaging, interactive still life compositions that mix everyday objects with elements borrowed from famous works of art.
While there is a print feature, it seemed a little buggy, so I just used SHIFT+APPLE+4 on my Mac to snap png images of my work. The finished products can be viewed in Preview as a slide show.