Bread Board Power Supply Shield (5V/3.3V compatible)
This is a power module for the standard bread boards (Small and Medium sized). It's concave design so will not wast your proto zone. It also supports both 5v and 3.3v (both can be enabled on each power rail).
We think it is a must to have on your workbench, really.
You can power it either with usb (easy) or with a wall wart (for more power).
There are two independent power supplies, one for 5v and one for 3.3v, that can be enabled separately on each power rail (say you can put both rails to 5v or 3.3v bot also one to 3.3v and one to 5v).