For a modern take on a traditional canopy bed, try bed curtains. Instead of being mounted on a canopy bed, these curtains look great hung from the ceiling. You can use a combination of standard curtain rods mounted on the ceiling to create this look.
27 Ways To Rethink Your Bed: Bed in a Closet. Also check out the Roll-Away Bed under a Platform; Cool way to quickly tidy up a small space, and keep pet hair off the bed! Maybe put a little reading or office space on top on the bed?
floating-bed - could do this for a boy to. Cool and fun idea. Gives more play room on the floor and also doesn't create clutter under the bed. Wonder if this would keep my kid from shoving everything under the bed when told to clean his room?