GNU/Linux Desktop Survival Guide by Graham Williams
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Enlightenment

Head over to e.themes.org, and find the themes you like. Download them, and put them in  /.enlightenment/themes. Then, restart Enlightenment (use the left-click menu). Now, you can choose your new themes from the middle-click menu. It's really pretty simple... I wouldn't worry about apt-getting that sort of thing (if you even can). There is supposed to be a tool that will automatically update your themes, but last time I checked, it was in the alpha stages. Can't recall what it was called, sorry...