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!
Reclaimed Barn Wood and Barbed Wire Tree Wall Art. This is about the ONLY thing barbed wire is good for. I could totally do this too. we have the wood and way too much crap barbed wire that I can't wait to make disappear.
Gotta make one of these out of our old barb wire fence heart barbwire