Selling your iPhone to buy an iPhone 3G? Here's how to erase your personal data first

With the iPhone 3G due to go on sale in a month, lots of owners will no doubt be looking to sell their old models before they upgrade – particularly since O2 will be offering iPhone PAYG SIM cards that letes you use an iPhone on the cheap.

The problem, as we reported last month, is that it’s impossible to completely erase all of your personal data from the iPhone using iTunes alone. The recovery process may be complicated, but that’s hardly reassuring for anyone looking to flog their phone on eBay.

The good news is that Jonathan A. Zdziarski, who discovered the post-restore lurkage of personal data in the first place, has now posted some steps that will fully erase an iPhone. The bad news is that you need to Jailbreak your iPhone to do it (which is trivial with a tool like Ziphone) and you need to be prepared to figure out the location of an iPhone utility (“This can be found on the RAM disk, or in other places. Don't ask me for it” – natch), then waiting an hour or two for the process to complete.

Hopefully someone will come up with a simpler one-click application that’ll do the same thing, but until then, you can read the full details over at Jonathan’s blog.

[Zdziarski.com]