Car Power Inverter for Macbook?

I'm going away on a trip soon, and want to be able to charge a macbook but won't have access to any power supply except for the cigarette lighter in my car. Apparently I need a power inverter to plug a macbook into the cigarette lighter.

I went on the apple website, and they had a power inverter, but it cost more than I wanted to spend on a power inverter. So instead, I went to a local auto zone, and bought a power inverter from there for less than half the price.

It's made by Schumacher, and it's a 70 watt power inverter. The front of the package says "Converts 12V DC car power to 110-120V AC home power". Here's a link to the inverter on amazon, Amazon.com: Schumacher PI-70 70 Watt Power Inverter: Automotive

Here are the specs:
10 Minute Continuous Output - 70W
Continuous Power Output- 60W
Surge Capacity (0.1 second) - 150W
Full Load Input Current- 8a
Optimum Efficiency- 85%
No Current Load Draw- <0.2A
Output Frequency- 60Hz+/-2Hz
Output Wave Form - Modified Sine Wave
Output Voltage Range- 115V+/-5V AC
Input Voltage- 12V DC
AC Receptacle- NEMA 5-15 USA

The package says it's meant for laptops, but I've been looking online and have read that the wrong inverter could screw up the macbook. Does this inverter sound like it will do the trick? Do I need an inverter higher than 70 Watts? What should the specs be on the inverter I use?

Thanks for all your help

NOTE: Thread moved to appropriate forum. Not just anything goes in Anything Goes

I'd say go down to Radioshack and pick up a 150 watt power inverter for like $40. I'm pretty sure the Macbooks need 65 watts and the Pro's need 85 watts.

Seems like these guys think the same.