Well, I finally shot some 35mm film in my Holga. Yes, folks, as if it's not crazy enough to use a $20 medium format camera with a crappy lens and only one shutter speed, you can jam a roll of 35mm film in and it'll expose all the way to the edges. Photographer Richard Sintchak showed me how to load the film a few months ago, and photographer Susanne Friedrich shot my portrait with a Sprocket Holga last year.
The process is pretty easy -- just cushion the roll of 35mm with foam, customize your 120 take up spool with some format reducing rubber bands, and tape the heck out of the camera.
A general rule of thumb when winding between shots is to go 34 clicks. Frame spacing will be tight at the beginning of the roll, and then you'll have gaps as you get towards the end. Nicolai over at Photon Detector has an excellent winding chart for getting more even frame spacing and being efficient with your film. Some people even tape a winding chart to the back of the camera. Just cross out each exposure as you go.
And if you're tired of carrying a changing bag to unwind your 35mm film in complete darkness, Randy over at Holgamods sells a 35mm Holga conversion that allows you to rewind the film in the camera. I can't wait to do some sprocket Holga night photography!