The best method to recharge might depend somewhat on your projected touring m.o. and the route(s).
I had great performance from an inexpensive phone charger. 30 bucks, small and light, and provides 2+ iPhone charges. I read about a divide rider (here, I think) who used a couple of them with success. My charging needs were limited to a phone, and it does take a few hours to recharge the charger using a regular 120v outlet (like you'll find along the walls of many restaurants, laundromats and some RV park tent campsites).
http://www.monoprice.com/Product?c_id=108&cp_id=10831&cs_id=1083110&p_id=9283&seq=1&format=2