Emaewest, these are my favorite beds too. Love going out there and snip a salad of mesclen mix and asian vegs without bending over. :} I have a bad back too.
I use alot more herbs in cooking ever since I did this because it is so easy to get them.
I have also grown tomatoes in them and let them cascade over.
Lots of people come to the garden and they all gravitate to these beds.
Anyway, they are made with drainage pipe cut in half and wood. Here are some close up shots and photos from 2005 garden:
