Ditch your mini-USB cable to power your Raspberry Pi. It’s much nicer to power it using an Ethernet cable. The nice thing about Power over Ethernet is that you can power your Raspberry Pi in places a USB power cable could not reach. Maybe you want to mount your Pi on the ceiling or in the garage. With PoE, you can power the Pi almost anywhere an Ethernet cable can reach (with a maximum distance of 100m).
Two Items Needed (For Most Users)
Xtronix makes a Power Over Ethernet Adapter for the Raspberry Pi (A, B, B+, 2). They are a bit expensive at £67 GBP (about $84 USD) but you can purchase them from Xtronix’s eBay store. Get one for the original B+ model, or you can get this one that works with the Pi 2.
You will probably need to purchase one more thing if your home router doesn’t support PoE natively (it most likely does not). The solution is to buy a Power over Ethernet injector about $18), which plugs into a wall outlet and your router.
Being funded now, there is also a project on IndieGoGo, which has a similar add-on board for providing power over Ethernet.