>Can the R09 be powered thru USB

Because I just bought a USB 'stick' that takes 4xAA's, for my ipod,
>but if it powers the R09 as well, I'm set

I don't think the R-09 can be powered through the USB as the USB just allows the R-09 to connect to a PC, the USB connection is not used at all to charge or power the unit. Probably some other recorders could be run that way, especially if they have an internal "rechargeable" battery that is charged via the USB connection.
Plus, the USB port on the R-09 is inside the bottom door, so you'd have to leave that door open half way just to allow access and that wouldn't be too good for long periods of time.
I always run 2 AA energizer lithiums on my R-09 for each show and I could easily do 2 shows with them, around 8 hours at least. Once I run the pair for one show, they then become the "back-up" pair for the next show, then after that they go into a box to be used for other gadgets like TV/dvd/cd/cable remotes, etc. until they are fully used up.
I have used rechargeables long ago to run my M1 DAT, but unfortunately sooner or later rechargeables will bite the dust, and I already had one scare where one pair almost took a dive at a show and that was the last time I did that. For all that goes into capturing a show and the fact that you only get one chance, the cost of the lithiums isn't much when it gives piece of mind on that issue.