I have just finished making a pinhole lens for my Canon 5D... drilling a hole in body cap and making the pinhole from a piece of aluminium drink can. My first tests indicate the aperture is around f180 and this particular one seems quite good. Earlier versions were around f90 and I found them a little soft (although quite useable considering that would be the point of using one). I even made a useful lens shade out of the top of a spray can...
Being on a digital camera and using 3200 ISO, I can hand hold in daylight with typical shutter speeds around 1/30th second, which is rather handy. I guess I would use a tripod and lower ISO settings in a landscape setting as slower shutter speeds would be useful for movement blur in water and foliage in the wind.
Here are some initial test shots in the back yard... now to find some suitable subject matter...
