Blew up the arduino

I was making some progress on my amp, and got the status LEDs wired up. Then I accidentally shorted out the the 5 volt regulator and blew up the arduino. The 5 volt regulator is fine, but the arduino is toast, it's a dead short between its 5 volt pin and ground.
Fortunately they only cost about $3 and I have two more spares.
I'm going to wire up the new one differently, and put a protection diode inline with it.