if you have all your media on your itunes and other files backed up in itunes (backs up on sync by default) then you shouldn't lose anything
No. Replacing the battery will not wipe the phone. Make sure the phone is off before you disconnect the battery though!
You erase everything from your iPod by connecting it to iTunes and click on iPod and click on restart.
you go to your history and erase everything
There are many retailers that sell affordable dry erase calenders. Target, Office Depot, and Office Max are some retailers that sell affordable dry erase calenders. You can also go on Amazon to find cheaper dry erase calenders.
the same way with all of the other iphones
restore it on itunes
To sell a laptop, you will need to erase everything on the hard drive before selling it. There are hard drive erasers available which are free of charge.
http://www.webtree.ca/windowsxp/repair_xp.htm
You cannot remove everything off your profile.
All you have todo is attach the iPhone to your computer insure iTunes is open and then select restore to factory settings options, which will reset the handset and erase ALL previous data.
Actually, It doesnt. 'Cause its the purpose of backing up the data. After the update, Your iphone will restore then it will put back your old data.