On my desk I have lot of things which require power. USB hubs, developer boards, customer devices etc. So far I counted 3x12V (ngw100, at91sam9263ek, edb9301) and 4x5V (usb hubs, beagleboard, bug). I do not count under desk devices because there is more space so extra cables from power supplies are not a problem (voltage is more problem as they use 6V, 9V or other less popular ones).
How to power all of them? So far I use few 5V power adapters (originally made for Sharp Zaurus, HP iPaq or usb hubs) and one 12V one (so only one 12V devboard at time). This has to end as it occupy too much space and power sockets.
So I bought old 200W ATX power supply in local computer shop specialised in old devices and parts from them. It is small but works. Now I need to buy few meters of cables (two colours — one for 12V and other for 5V) and do soldering job. The good thing is that ATX PSU require shorting just two cables to power up (PS ON with GND).