Even if your apps aren't there, and no personal information has been entered on a fresh wipe. If someone asks for a stock Nandroid backup, kindly tell them to get lost contagous and I learned the hard way. I sent him a completely tweaked and clean nandroid, with none of my personal info or anything like that. He has been using it and it works great. Until AppBrain fast web installer is used. See, it IDs your device by the Android_ID, which is unique to every phone, or is supposed to be. Nandroid backups will record this device ID, and clone it onto another device. Well, when contagous installs an app using the web installer, I get it. Without a prompt or nothing. While I can do the same thing, and it was fun sending him pron apps and sexy men wallpapers, it has a real potential for a security nitemare. I trust contagous, but let this serve as a warning to everyone. Its also not so simple as installing another ROM and factory reset. So far as I can tell, as long as you stay on the same build OS, you will keep the same ID. The only thing that changed my ID to something else was going back to 2.1. So friends, don't let friends share nandroids. If you do, play it smart, and delete all but the system and boot images and recalculate the md5.