Split power supply for 2 Arduino's

Hello,

I currently have an Arduino Duemilanove with a power supply wich supplies 12 Volts and 3.3 Ampere. But if the Arduino alse works on the 5 Volt of usb-power, is it an option to split the output of the power supply to connect 2 Arduino's on it?

Greetings

Get / make a Y-cable for the 12V supply and connect both arduinos separately OR use the Vin pin on 1st arduino to power the 2nd one (still you have to end this cable with this jack-plug to let 2nd arduino use its onboard voltage regulator), but I don't think it's a reliable connection. I'd go with the Y-cable.