power supply for car GPS

I have recently purchased a HP ipaq with tom tom installed for use in my car, it sits in a ThinkNav GPS cradle that is powered by cigar lighter, my problem is I want to use it in my aircraft as a navigational GPS with CAA software but it has not got a cigar lighter, is there an external power supply on the market that could be used to power the GPS cradle and could be recharged.

Please help.

[Stevie]

You could hook it up to a battery.