This is just so handy. It makes working with breadboards so so much easier, I find that I'm much more willing to quickly experiment now I have a prototype battery basically, rather than having to wire the board to a plug/computer. Also it means I can demo the board anywhere.
Bought two Megos for my electronics projects, working well so far.. They are designed to be compatible with breadboards, basically you can push the Mego onto the breadboard and its power pins go directly into the power rails. Also has variable DC voltage range that cover the requirements for all of my projects, great alternative to bench-top power supplies!