I spent way too much time choosing a dynamo hub, building a wheel, having a friend build a circuit so I could charge my phone while away from home.
One day I was randomly surfing dealextreme/ebay and stumbled on something that was unbelievably awesome: cheapass solar power. Turns out a $25 solar panel and a spliced usb cable is enough.
At this point the main benefit of a dynamo hub is that it works all year long(24x7 as long as I'm biking). Dynamo also has a benefit of being a bunch of metal that's part of the bike. Attaching a solar panel will require some cleverness to avoid smashing it the first time the bike falls over.
On the other hand the solar panel is light and will work great for camping while off the bike. It's good to have options.
- I've had this for a while now. This solar panel is amazing. It is exactly as the seller claims: 5V and provides up to 700mA of current. There is a problem where if the panel gets in the shade, the current level drops off and stupid charging circutry on my Vibrant continues to try to charge. I documented it in this forum post.
- ebay listing I bought this from.