120V AC inverters are *notorious* for noise in the line. The cheaper ones, espeically so.
This noise, unless filtered out properly, will cause interference in electronic devices like laptops and cell-phones. If you have a *high-quality* surge-protector (like Panamax or APC -- something in the $30+ range) then maybe you can plug that into your inverter and it will filter out enough of the noise to make the inverter useful.
But if you're going to go through all that trouble, why not just buy the Droid car-charger for $22.49.
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