I've seen some neat looking cat shelves on Moderncat (www.moderncat.net)
They have several DIY projects using shelves too: http://www.moderncat.net/category/diy/
Also--
"Refined Feline" cat shelves
http://www.therefinedfeline.com/
"Urban Pet Haus"
http://www.urbanpethaus.com/content/perch.htm
"Curve" pet bed
http://www.akemitanaka.com/curve.htm
They have several DIY projects using shelves too: http://www.moderncat.net/category/diy/
Also--
"Refined Feline" cat shelves
http://www.therefinedfeline.com/
"Urban Pet Haus"
http://www.urbanpethaus.com/content/perch.htm
"Curve" pet bed
http://www.akemitanaka.com/curve.htm