Chris Meierling recycled old shipping pallets into a lovely home office and bike storage system that I showed on TreeHugger here. The pallets provide an interesting background for the bikes (as does the red paint) and can also support other types of storage. He writes (without explaining exactly how the bikes are hung):
The pallets shelves were rough and dirty. I picked 4 pallets up off a nearby street, made the shelves, and screwed them directly into my drywall with drywall anchors. Each pallet had about 10 screws across the pallet to distribute the weight; each anchor had a 40 lb hanging capacity.
More on Flickr.