Palmpilot
Touchdown! Greaser!
Also, many aircraft give you access to ship's power, and the appropriate adapters are readily available.Never really worry about batteries dying in the iPad since the 430 does a good job of showing the flight plan (on a tiny tiny screen, but it works). Even if that died, I am confident I could get to where I'm going or get home pulling out the sectional I still carry. Lots of good landmarks around and I can hold a heading (and I fly with flight following so vectors are always an option as a last resort).