Elmer's Glue on Canvas, then paint the whole thing. I have totally done this, but with a hot glue gun. Elmer's Glue seems to be a better idea since hot glue leaves behind strings and is harder to work with.
Memory Candles: This is such a fun way to display photographs! The technique uses black and white photocopies and transparent contact paper to transfer images to glass votive candleholders. What happens is that the black ink sticks to the contact paper.