I faced the same problem that I'm sure many avid cyclists have- "Where do I put all these bikes?!" I have a mountain bike, a commuter/utility bike, a fixed gear, a bike polo bike, and my wife's hybrid bike too. I used to keep them piled in my basement but every time I wanted to ride a specific bike I had to move 3 other bikes out of the way to get to the one I wanted.
I knew there had to be a solution but my searches for a storage solution were nearly fruitless. I found several different styles of bike racks online but everyhting I found shared 2 common elements. They were all overpriced (generally $200+ if I hoped to store 5 or more bikes), and they did not appear to offer much in the way of space savings over my current method. I knew there had to be a better and cheaper solution. I keep a couple 18"x24" whiteboards in my garage because I'm a visual person who needs to see things to fully understand them. I spent a few evenings in my basement with a tape measure and my whiteboards measuring the bikes and the room and sketching designs. After many scrapped ideas, I settled on a modified A Frame design that would be pretty easy to make with basic tools. I loved this design because it could store 5 bikes in the space of 3 without compromising the ability to get to any bike at any time. A $25 trip to the hardware store later I was ready to start building.
It came together pretty easily and now that it's complete the rack works just like I'd hoped. 3 bikes on the bottom and 2 bikes on the upper level with space for the future addition of a shelf inside the "A" frames to store a bike pump, chain lube, and some spare tubes. The upper bikes stay in place just fine but I did add bungee cords to secure them just in case of an unexpected earthquake or Godzilla attack.
It's not the prettiest piece of furniture I own, but it gets the job done and for 1/8 of what I would have spent on a ready-made unit I'm happy.