The IPAC has a 5v header on it IIRC, but it will only supply 5v when it's plugged into USB as far as I know.
You can make it work easily for PC by just connecting the 5v for the P360 to the IPAC header. The Xbox controller port also supplies 5v as it is basically USB as well, however I'm not sure how easy it would be to grab that 5v from the Xbox adapter. I don't have much clue about the PS2, but I'd assume it would output the 5v as well, but that's just a guess. And again, how easily you could tap that 5v from the adapter I don't know.
I'm not giving you a ton of info unfortunately, but maybe something will grab the attention of someone who knows more about it than I do.