What is pinhole camera shooting? Can it be done with a digital SLR?

I agree with the other posters, especially the second There are two advantages I know of for a pinhole camera.
1. You have very good focal depth (foreground and background both in focus).
2. You can take a picture of something very bright, like the sun. Maybe you can use this next time there's an eclipse.

A pin hole camera is exactly what it says it is...and it doesn't use a lens. Check out the links below for an explanation of a pin hole camera...

Of course. Use an opaque body cap, drill a rather large hole in it (maybe 3/8") and then tape a piece of aluminum foil on the camera side of it. Then very carefully, use a needle to make a very small hole.

Using your camera in the manual mode, you can experiment to get the right exposure.