There's a great adage in the home decor and organization field...you've probably heard it on one of those room makeover TV shows. The phrasing varies, of course, but the central idea, "When you run out of floor space, you've got to go up."
Eric and his office mates came up with this clever DIY solution for storing a whole mess of bikes in a relatively small space - 7 on a single wall - using a super simple hanging system. The design mimics commercial wall mounts for bikes (I have three in my own garage), but is built from those DIY standbys - plumbing pipe and reclaimed wood. A length of inner tube is used to to protect the wheel rims and spokes.
Making one of these might not save you a ton of money over a manufactured one, but if you need to get several bikes on the wall, it's a great solution. And it looks pretty sharp, too.
Reclaimed Wood and Pipe Bike Hangers [Instructables.com]