MOTM

http://www.middle-atlantic.com/products/rack_en/19_knock/obrk.html

Check out the sloped racks at the bottom of the page.  We used one of these 
for a tradeshow.  Nothing too exciting, but they are inexpensive and work 
fine.

For more info on dealers, etc. go to:

http://www.middle-atlantic.com

Ivan