Universal Adapters

[Aspen42]

I'm looking for an adapter for my notebook for the car (my notebook's battery last only 3.5 hours) and possibly for an airplane; I found a few but I'm not sure what would be the best to buy:
Auto/Air Universal Adapters (generic brand)
Targus Mobile Power Inverter
Targus Universal Auto/Air Adapter

I would like to buy an adapter that I can use in both the plane and car but I'm unsure whether its worth the money or not.
Thanks for the help :D

[chrrox]

Radioshack sells universal laptop adapters they run about $120.00 usd but if your laptop is important to have on longer than 3.5 hours than definately invest in one. It should not matter what brand you go with as it is juat an power adapter just make sure the volts and amps match up and you should be fine.