Now that Apple has released OS X 10.9 Mavericks, you might want to consider creating a USB install drive for clean installs and future use.

An 8GB or larger USB flash drive, or an 8GB or larger partition on some other kind of external drive. The OS X 10.9 Mavericks installer from the Mac App Store in your Applications folder.

Getting Lion from the App Store is convenient, but if you want a physical copy of the installation, you can easily make your own Lion install DVD or USB drive with Disk Utility.

There you have it — a bootable copy OS X Mavericks on USB Flash Drive that can be used to install, upgrade, and/or troubleshoot compatible Apple computers.

OS X Mavericks is available in the Mac App Store now, but it's only an upgrade—but if you want to do a clean install, you'll need to manually burn an installation flash drive. Here's how to do it.

Jesus Vigo goes over the steps to create a bootable USB to install OS X 10.7-10.8 and OS X 10.5-10.6, as well as how to put multiple versions on the same USB.