I've always wanted to make a pinhole camera, ever since hearing about camera obscura in my high school photography class. Sounds fascinating.
Mike-- in reply to your inquiry about the "benefits" of pinhole photography: I found this quote on the
wiki page, and quite liked it:
"There is something special about a pinhole camera. There is a beauty in its simplicity and rawness that technology has not been able to better. There is a timeless quality that can make the most uncomplicated subject seem full of poetry." --Wolf Howard
I would also add that an advantage of pinhole photography is the ability of the photographer to make their own camera from scratch. I would be proud of myself if I ever successfully made a pinhole camera

which is reason enough to try! And I'm sure that making pinhole cameras would be a great learning process for 4th/5th graders, rmjannette. Sounds like tons of fun, too.
However, there are tons of disadvantages to using a pinhole camera (Not to disrespect the art! just my observations). From what I've heard, exposure times can be very very long. In the photographs I have seen taken with a pinhole camera, the vignetting around the edge of the image is very strong and few of the images are very clear. The wiki page also has some information about "reciprocity failure" which you can read about
here. (interesting stuff for a photo-geek like me!)
Anyway, sorry if I went on too long about that stuff. It's exciting. Yay photoblog forums!