Recycled door would make a great trellis. This has barbed wire spirals connected together to form a panel. Thinking barbed wire would not be so good as a trellis, as the yearly clean out of dead vines would be a bear!
Using a rain barrel can save you a significant amount of money in a season. For each inch of rain that falls on 500 square feet of roof, you can collect 300 gallons of water to use in your garden, or your lawn. If we ever got rain.