Would this just be a full wave bridge rectifier?

I used to do that (4 diodes) for batteries AND powersupplies when I built my own guitar effects board power source. I was tired of either putting things in the wrong way and either a) not working or b) frying some electrolytic capacitor (if was a high current supply).

http://en.wikipedia.org/wiki/Diode_bridge

Seriously - is it just that or did they find a way to make it have low enough resistance to put in every device ?