I've flown a bunch of times domestically with my gp, and or a laptop. I've never had trouble with either them being in cabin luggage or in cargo. I suppose mechanical shock is possible, but the xray machines don't do anything to them. The rule with all the airlines I've travelled with (not many to be fair), is that you can't have them switched on 20mins after takeoff or 20mins before landing.
the gp is great for flying, it's not huge like a laptop and when you wanna sleep you can chill to some quiet tunes... well i do.
I also carry other electronic goodies for work, things that you might expect to be damaged by xrays (well i would have thought so); usually stuff with some sort of non-volitile memory like CF cards, or eeproms / proms / fpgas. Weirdo circuit boards with lotsa crazy sensative stuff connected to them. There has never been a problem with the xray machine. I some times get some strange looks from the security people tho.