You can check out my video channel http://www.youtube.com/aquaponicsnyc
It is a small system but you could scale it up to larger tanks and growbeds.
You can also look up barrel ponics as Travis Hughey has written a wonderful free manual with step by step instructions for building it out of blue barrels. Manual link near bottom of the page at this link.
And there is the IBC of aquaponics which is a great resource for learning about IBC aquaponic systems.
Thank you both very much! I thought I'd just let the world know that aquaponics is taking hold here in South Africa - I am off to see my first system this morning, in Paarl (near Cape Town) and I would say that the general idea or concept of self-sufficiency is growing here rapidly as well. Just thought you may like to know...