If your town is safe enough that you can simply lock your bike onto a rail, they are really useless (sort of...).Most of these seem like excuses to make you pay for parking your bike. The reason I ride a bicycle is that it comes off cheaper than any other mode of transport, so I would avoid things like this if they existed in my town.
In Tokyo I came across this underground bicycle parking system, it's quite nifty.
WOW! That is really, really clever.