Hey folks, thanks for all the insight! I should mention a few things: First of all, as Rowan mentions, I like the idea of having a back up; not just for losing lights, but this will be a solo ride so losing navigation or the ability to call people could be kinda antagonizing. Second, I do commute year-round and this bike would probably see a good deal of commuting time after the ride. My phone is an old flip phone (doesn't even have texting), so I do want the GPS for navigation. Lastly, I do like the idea of running lights during the day if it's rainy or dark.

On the other hand, the phone could easily be charged up at stops; the battery lasts a while and I don't plan on using it much. I certainly could get by with maps as well but would like to use the GPS. Time is also not an issue on this ride (I'm taking the semester off to save up & ride it, so I want it to last a while!), so realistically a rechargeable pack would work.

I guess I just need to decide what the value for commuting, using the GPS and having a constant power source plays into the price of the hub. I'm buying a new bike for the ride, so I realized that if my LBS will credit and swap components on the bike the hub price is really reasonable. I'll have to talk to them about that...

You folks who have had luck charging GPS/gadgets with your hubs, what kind of hub did you choose? Do the SONs really put out a noticeably higher power? Anyone know where to find an estimated current and voltage output for the different hubs on 700c wheels at a given speed? Right now if I go the generator route I have my eye on the Shimano DH-3N72. Any critiques of that choice?

You've given me lots to think about, thanks so much for the input!
~Nick