CO also sells the Empower plugs (the Juice brand I believe) on international flights as part of their duty-free offering. They were selling pretty good on a flight to Tokyo a few weeks ago; I think the cost was $100.

As with other seat features though (i.e.: audio), I've found Empower to be come & go; some seats the power is busted, on others it works fine. It is a shame they don't offer more of it on domestic flights, especially with JetConnect and internet connectivity becoming more common.