I've been meaning to do a wall collage at the lake for the dozens of photos we have of people skiing/tubing/surfing behind the boat. I half-heartedly stared a few years ago by printing a couple on canvas, but never finished the task. Last year, after I captured a particularly epic photo of my brother and nephew, I tried printing on metal through mpix.
I LOVED the way it turned out. It's a sleek-er, less-casual alternative to printing on canvas, and the price was comparable. It's more modern looking, and shinier. Plus, like canvas, you don't have to worry about framing it or hanging it. It comes with all the hardware you need on the back, and they're meant to be frameless.