For only $350, you too can build a secret doorway out of a bookshelf [1] (link via Antarctica Starts Here [2]). Makes me wish I had the space for something like that.
[1] http://www.instructables.com/id/E4Z8XHRF1A4XXOA/
[2] http://drwho.virtadpt.net/archives/archive_2007-m07.php#e474