Every electronics project needs power. You can spend a lot of time building supplies or a lot of money on batteries. If you build projects to use in your lab you can use one supply with a lot of projects plugged into it. Then just cable up the project and plug it in. In this project I describe a way that I have done this that I thinks works out pretty well. I use mostly salvage parts, but you can adapt it to other parts, and buy them if you wish.
http://www.instructables.com/id/Almost-a-Power-Supply/