powering the arduino

i am currently using the usb cable to power the arduino duemilanova

ok, so i know that you can use a power source dc 7 - 12VDC that can be hooked into the Vin connection on the duemilanova

the othe rquestion is this

the jack connection that sits on the board can also be used to power the arduino

does anyone know exactly what kind of powersource must be used to provide power via this connection

from what i've seen it doesn't say much is evasive or contradictory

i watched a "collin lab" vimeo about power supplies and he picks up a plug pack 9VDC and declares you can use this to power an arduino device he holds in his hand

the official blurb about this connection mentions nothing about what kind of voltage or recommendation , is it it safe to assume that the voltage you can put on the Vin pin is the same voltage you can put on the jack connection?? its positive for the central pin i think

You are correct. The center pin of the power jack is the same as the Vin pin. The outer sleeve of the power jack is the same as Ground.

thank you!!!

i just didn't want to make a fatal mistake and blow up the arduino!!