factory reset - What's the most complete way to erase all the data from my phone so it cannot be recovered?

I just got my replacement Droid and will be sending my current Droid back to Motorola. I'm sure they are going to refurbish it and resell it. I've backed up everything and I'm going to be keeping my microSD card, but how to ensure that all the data is completely wiped off the internal memory so there is no chance that it can be recovered by someone else?

Answer

Perform a factory reset then write to the memory and reset again. This is the best way I have found to prevent data remnance.

I was aware that with a magnetic based drive there is almost always data remnanace. I believe the standard to effectively erase info on a magnetic drive is erasing and re-writing over the drive 7-20 times (don't quote me on those number). I was under the impression that once you erased data from flash storage it was gone for good but recalled the story of a woman finding porn on her refurbished Evo. So, I asked about data remnance at Superuser on flash memory and found that data sometimes can remain after it is deleted. The recommendation there was: formatting, writing to the memory and formatting again.

To format, as the answers above suggested, I performed a factory reset. This can be done one of two ways on the Droid:

1. Go to the "Settings" menu, choose "Privacy" then choose "Factory Data Reset"


2. Do a hard reset

Ultimately I just did the Factory Reset because I was too lazy to load the system memory up and I suspect that 99.99% the Factory Reset is sufficient, but it's good to know what the risks are.