if you have a mac book air be warned that lion will disable your ability to borrow a disc drive from another computer. no more music uploads from cd!!!!!!!! went to the apple store today to see if there was a fix and was told sorry, just buy this 90.00 external disc drive to restore the functionality lion took away, and maybe apple will fix this. ARE YOU KIDDING ME? there was no warning of this when i Upgraded -- and i use that term loosely--to lion. BE WARNED .