Running multiple miners from a single PSU

[joesixpack]

Has anyone ever used a larger transformer (or whatever the appropriate name is) to power multiple miners at 12-volts?  It seems like if you have more than a few, it's inefficient to have each one running it's own power supply.  Is this even possible?

I've looked at a few different pieces of gear online, and it seems like it would use less power and generate less heat.  Has anyone done anything like this?