iPhone 2G restore - old data really gone?

Hi...

I'm selling my old 2G iPhone and want to know that all the old data is truly unrecoverable after doing a restore.

The restore process seemed to be successful though I wasn't in the office to see it all. With the SIM card still in the iPhone I connected to iTunes and clicked Restore. Now, with the SIM card still in it, iTunes wants to go through the activation steps and the phone won't allow anything except emergency calls.

So it all looks good but there's no way for me to verify all the old data is truly unrecoverable. I wouldn't want anything to get to whoever buys this phone after me.

ATT told me to do this:

Settings > General > Reset > Erase All Content and Settings > Erase iPhone.

It took a long time. Way longer than a restore. Not sure if there's anything different though from what you did. I got the same activation screen and everything like you did after.

Rats. Well now that I restored I can't get into the Settings to do that.

I'm pretty sure that the complete restore will get rid of all your data though as well.