I am thinking of grabbing a bunch of these:

http://www.mcmelectronics.com/product/DISTRIBUTED-BY-MCM-CK-0027G-/83-11765

They are available from a local store for $6.75, and have a 3.5A power supply ( I physically looked in the box).  Due to the configuration, I only think 6 ports would be usable though.  However, that is pushing $1/port!