I have a very simple one - a Daylab 4x5 pinhole camera. I saw it at the Photo Expo in NYC one year at the Daylab booth and ordered one. It takes the Polaroid i545 back. I thought it would make a good intro into the pinhole world.
I remember making a shoebox pinhole when I was 10 or 11 for the school's science fair - how many of those have been made, eh?
So whatbrand of pinhole do you have?