I bought this rack a while back:
http://www.oceanswondersonline.com/c...25.htm#image_1
Same basic idea. The only problem is with the square magnets. They don't seem very stable, and can easily "flip" over when jostled, sending the rack over and the frags to the bottom of the tank. I like the design of your rack better, as I think the flat round magnets would be more stable. I'll see if I can't get a picture up in the morning.