Here’s how to make DC Bicycle pedal power generators from the folks as Science Shareware -

Here you can learn to create your own green power electricity using a pedal power bicycle generator. We setup the 24 bicycle power generators at the 2007 Coachella Music and Arts Festival, 60,000 people a day for 3 days in the desert – Indio California. The bike generators were used for charging cell phones.

DC Bicycle pedal power generator – Link.