I do both. I use a Zero Image 69 which is my workhorse but I also make 4x5 pinholes. 4x5 are easier to make because you dont have to deal with the roll film mechanism. That being said a good compromise to homemade roll film based camera would be to convert older 35mm and medium format cameras to pinholes.

This is the 4x5 pinhole that I build:
http://www.flickr.com/photos/bokchoyboy/4556489136/