I have loaded 35mm film into my 120 holga and...?

Putting foam underneath the canister should work fine. The point is to hold the canister in place and not allow it to move up or down in the 120 film compartment. Photos taken this way are very wide, compared to a standard 35mm frame. If you get your film processed at a regular 35mm lab, they will most unlikely be able to print your film full frame, since the 35mm Holga neg is much wider than the 36mm of the standard neg. They also won't be able to print with the sprocket holes, because when 35mm print equipment was designed, the sprocket holes are considered non-print area. For prints or scans, you will need to find a lab that can handle not only 35mm film, but medium format film as well. The cheaper and easier way of dealing with film shot this way, is to scan it yourself. You will be able to take the digital file to a digital lab to get prints, and you can also include the sprocket holes if you want. Take a look at a medium format scanner like the Epson v500. These are fairly reasonably priced. For more lo-fi info, check out my website: http://dianacamera.com/ for how to videos for your Holga or other lo-fi camera, visit my youtube channel: http://www.youtube.com/kaituba