I'm going to do this as a photo Instructable as it was so quick and cheap. Over here in the UK we have a partial solar eclipse on Friday and I've been really disorganised. We do have eclipse glasses but I wanted something the children could look at throughout the eclipse. I had a spare pinhole, but even if you made that from scratch, I reckon you could do this in well under an hour. According to the Royal Astronomical Society this is the safe way to do things, as to view properly you have your back to the sun!