Bicycle parking is an important element in urban and building design. Well done, it encourages bike riding by giving people secure places to lock or store their bicycles.
Bike parking can be divided into two main classes, open parking (racks for visitors) and enclosed parking (for building residents and workers).
I think the standard U, or STAPLE has a utilitarian charm.
Racks can be ganged at 24" centers, allowing two bikes per U. The most important design criteria for U-racks is leaving clear access space on both ends. Frequently designers put a row of racks up against a wall or other obstruction, reducing their capacity by 50%.
Businesses are installing bicycle parking for their employees and customers that ride that is in the public areas instead of hidden in a garage or store room.
This type storage is for residents and/or workers in a building. Although it can be accomplished with U-racks, a secure bike room is a much better option. Thieves steal bikes, and parts from bikes, even in locked garages.
As bicycle use increases in urban areas, there needs to be bike parking located in the public realm. BIKE CORRALS are starting to be a common feature in bike friendly cities. Amsterdam has a multi-level bicycle parking garage located by the main train station.
Many standard racks are poorly designed, such as the "wave" rack. It's better if the rack functions well as well as looks cool (not impossible, but requires some thoughtfulness)..