craftgrrl | Ideas for hanging canvas panels?

I've been doing a lot of painting on canvas panels lately (like these http://www.dickblick.com/zz070/08/), and have a decent amount of works that I'd like to hang, but some of the canvases are too heavy for my usual method (small binder clips on top, then hung on wall).

Does anyone have any super-cheap ideas for hanging these? I'm completely avoiding frames - they're expensive, add weight, and throw off the proportions of my paintings. The only other thing I can come up with is a sort of display ledge made of moulding with a groove for the bottom edge of the canvas, but I wanted to see if anyone else had other ideas.

Thanks for any and all help!!