The problem with dynamo powered lights and touring is, you need a separate light to use when in camp and/or fixing the bike by the roadside. In that sense, USB rechargeable lights like the Fleas combined with the dynohub+charging device seem like the best option. It gets expensive though, if you compare to cheap AA/AAA battery powered lights and a small NiMH wall charger.
Pretty much all my electronic touring gear (GPS, lights, radio, camera) operate on AA/AAAs and I try to keep it that way. One notable exception is my phone, but I believe I could find AA/AAA powered USB charger (essentially just an active USB port) to take care of that.
--J
Last edited by Juha; 10-23-12 at 02:32 AM.