Ben Crair sings the praises of the gibbon, and he's goddamn right. If you live in a city with a zoo, and that zoo has a gibbon exhibit-- go. They're just incredibly graceful and athletic creatures. Many zoos have gibbon exhibits with ropes hanging from the ceiling, or swings or similar setups, so that the gibbons can show off their acrobatics. It's astonishing how fast and controlled they are; if you've thought of Tarzan swinging through the jungle on vines, that's pretty much what we're talking about.
I haven't lived in Chicago for a couple years, so I don't know if this animal is still alive. But as of 2 years ago or so, in the (free) Lincoln Park Zoo gibbon exhibit there was a one-armed gibbon. He lost his arm after sticking it through the cage to try and get food from a zoo patron. With one arm, he can't swing the way other gibbons do-- but he's still remarkably mobile. He used to grab a rope with his one good arm, secure it under the armpit of his stub arm, and swing to the next rope. When he wanted to climb upwards, instead of climbing two armed like the other gibbons, he would stick the rope under his stub arm, then use his other arm pull himself up bit by bit.
I would watch them for ages when I went down to the zoo, and him in particular. He seemed to me to be a great symbol of overcoming disadvantages, a natural one, one which lacked any of the subtle condescension or pity that often marks those things. There's no fuss or angst, just an animal with a disadvantage who makes do, and who receives appropriate concessions for his disadvantage.
They really are remarkable animals and I have a soft spot for them.