Medis Technologies developed a disposable fuel cell to power mobile devices on the go, which is supposed to sell under $20.

Medis Technologies is using borohydride alkaline solutions inside its Fuel Cells, different from the Methanol Fuel Cells developed in Japan.
Medis' first consumer Fuel Cell is marketed as a mobile power supply, giving users 30 hour talk time on mobile phones or about 60 hours of music playback on an iPod. Looks like the consumer power pack cannot be refueled. Medis Technologies apparently has a refuel-able power pack for military use.

We met Medis Technologies at the CES 2006. You can watch the interview to learn more about the product. Medis Technologies plans to sell the first fuel cells in Q4 2006. Full availability will be earliest in 2007 though.
More details on the Medis Technologies site.