Auto adapter for MacBook?

[VortexOfPain]

Can't seem to find much info on an auto adapter for a MacBook, what do you guys use when traveling? I have considered an inverter, but also like the idea of something more compact that can easily fit in place of my normal wall adapter.

 

[volvoben]

I also wanted a 12v adapter for working on the road, but eventually settled on an inverter. I even tried to find one for a friend's Dell thinking it might be a more common size, but to no avail (well, nothing under $150).

My inverter is rather overkill, 200w, but it has come in handy for a few other things, people needing to charge their phones but only having ac adapters, charging batteries for my cameras etc.

For portability it stinks, but I just leave it in the car anyway. Of note, it does get quite hot with load. I had it in an enclosed space in the summer while running a borrowed Pentium 4 based laptop that drew 130w and it started to melt the plastic around it. For $30 it was a great investment at least.