Securely Wipe iphone

[ZF]

1 ) Restore to factory default using itunes
2 ) Jailbreak and SSH into the phone
3 ) Download and Copy the binary "umount" to iphone
rapidshare.com/files/122525674/umount.html
scp <dir>/umount root@<iphone ipaddr>:/sbin/umount
chmod 755 /sbin/umount
5 ) Remount /private/var and / as ro
umount -f /private/var
mount -o ro /private/var
mount -o ro /
6 ) Wipe
cat /dev/zero > /dev/rdisk0s2; cat /dev/zero > /dev/rdisk0s1
7 ) Boot iphone into DFU mode and restore phone

SOURCE:
www.iclarified.com/entry/index.php?enid=1347