Meg and I are always looking to improve our tomato trellises. Last year we did a string suspension system, which worked very well, and we will certainly try again, but at our new digs we are really aiming for space saving practices. The idea for this trellis came from some photos of the trellises over at Path to Freedom. At the moment I can't find any specific photos of their engineering, but if you hang around their site long enough, you're bound to see them.
We used some inexpensive plastic garden fence for the plants to climb. We'll have to make some of the holes bigger, but it should last us a long time.
Unfortunately the only part of the project that was made from reused material was a ten-foot piece of metal pipe we found in the basement. We'll get better with this as we learn what's available around us.
The trellis is about six and a half feet tall and each panel is four feet wide. We have a second set of panels to erect next to the ones in the photo, but we ran out of staples for the plastic fencing. We'll hit the hardware store tomorrow and call the project done.