Originally Posted by PaulRivers

If you're planning a long trip, I would still recommend the Luxos U - someone else mentioned that it's the same cost as a separate charger anyways, and it would give you a backup light if you accidentally need to bike at night after all.

I'm a tiny bit confused by saying laptop and "computer" - maybe you mean a speedometer? I mean a wired speedometer doesn't really need anything to charge it, the tiny battery in there will last for years and years without needing to be replaced. (And I don't know of any you can recharge anyways.)

I mean you get a very nice light

That runs off of a dynamo and you also get a charger via the dynamo at the same time. This is as efficient as you're going to get for your headlight.

If you could keep most everything else on your cell phone (gps is definitely something you don't need separate if you have a smartphone) you could just leave your cell phone plugged into the usb charger most of the time...