OS X 10.7 Lion installs a suite of recovery tools onto a new partition, obviating the need for recovery disks or even the new USB drive that comes with MacBook Airs. The suite includes classics like Disk Utility and new tricks like a “Boot into Safari” option to get support even if you can’t boot into the OS, or Internet Recovery if you need to download and reinstall Lion from scratch. Just hold Command-R during boot to launch into Lion Recovery.