'''WARNING - Hack ahead!''' For Time Machine users only.
There is an unsupported way to enable using Mac OS X Time Machine to backup to your HDA. The hack is [documented in this page | [http://vowe.net/archives/008940.html| documented in this page]] and it's a one liner command to be typed in a terminal in Mac OS X:
<code>defaults write com.apple.systempreferences TMShowUnsupportedNetworkVolumes 1</code>