My kids each have a 3" 3-ring binder with sleeves to put their special art pieces in. My 5 yr old in particular generates massive amounts of "art."
We don't have a toddler/crawler in the house at the moment, but I got tired of the fridge art. It was completely covered, and when my son ran out of space, he'd hang the papers off the edges. Opening the door knocked the papers off. So we tried to think of another solution.
What we did is save up lids from frozen juice concentrate cans (this takes a long time!) and hot glue them to a big sheet of cardboard. I did this when I was painting the wall, so I just used the roller to paint the cardboard, then glue the lids on, then paint the lids. It's fairly unobtrusive because it's the same color as the wall. Then I used Command strips to mount it on the wall. It's a cheap, big magnetic board for all my boys' projects. Ours is down low, but you could hang it higher. It needs decently strong magnets so walking past it doesn't blow the papers off.
I also mounted a cork board (but you could find a magnetic one) with Command strips to the back of our pantry door. If you want it to show, you could do it on the front.
Someone had the idea to make scrapbook page display frames. You can get project directions here:
http://networkedblogs.com/p14344233
Because they're square, they had to buy custom frames. You could buy a large picture frame (especially a cheap one with no glass at a yard sale--there seem to be TONS of them!) and get some sheet metal cut to fit in it. I have no idea how much sheet metal costs, or how much to get it cut, but you could look into it. Come to think of it, I may do that myself!