Bicycles can definitely get in the way when parked against the wall in a small apartment. That's why Dublin-based entrepreneur Sinead Geraghty created the Stowaway. It's a pulley-based system that lets you store your bike up against the ceiling.
To use the Stowaway, your first attach two of its loops to the handlebar stem and seatpost of your bike. You then pull on the strap to which they're both attached, which raises the bike straight up off the floor. Once it's at arm level, you then attach a second strap to its wheels. Pulling on this strap swings the bike sideways toward the wall, until it's flat against the ceiling. To get it back down, you just repeat the process in reverse.
The straps have a braking system, so they (and the bike) will stay in place if you let go of them. Additionally, the length of the horizontal yardarm-like bit can be adjusted to fit different bikes and different rooms, plus the Stowaway incorporates a counterweight system – this means that you're only lifting half the weight of the bike.
If you're interested in the Stowaway, it's currently the subject of a Kickstarter campaign. A pledge of US$107 will get you one, when and if they reach production.
For a more deluxe take on the same general idea (but one that's intended for installation in garages), check out the flat-bike-lift.
Source: Kickstarter
This would be great for cases where you have a shared apartment entry with a couple people and don't want to park your bicycle in the way. You could probably even combine it with wall hooks and use both depending how many bicycles you need to fit.
This Stowaway design is similar but simpler than another that uses a frame with pneumatic cylinders to swing a bike up flat to the ceiling.
The Stowaway has given me an idea for an even simpler/cheaper way to do the same thing. You just need to have a lot of open ceiling space rather than a lot of wall space (if you have a dozen +/- bikes to store).