A package called «android-tools», which comes with «adb» and «fastboot» command line utilities, has been uploaded to the Ubuntu 12.10 Quantal Quetzal repositories recently. I’ve got a request to upload this package in a PPA for older Ubuntu releases, so I’ve backported it to Ubuntu 12.04, 11.10 and 11.04.
«adb» (Android Debug Bridge) is a command line tool you can use to access the file system from an Android device; it can be used to send commands, transfer or receive files, install or uninstall applications and more.
«fastboot» is a command line tools that you can use to flash the filesystem on Android devices over USB.
These tools can be found in the Android SDK too; using the official package in Ubuntu 12.10 or the packages in our PPA is just an alternative and easier way I’d say, to install them in Ubuntu. Also, the packages in the PPA are available for both 32bit and 64bit, while the Android SDK provided by Google is only available for 32bit.