http://techcitement.com/culture/the-best-birth-control-in-the-world-is-for-men/"With one little injection, this non-toxic jelly will sit there for 10+ years without you having to do anything else to not have babies. Set it and forget it. Oh, and when you do decide you want those babies, it only takes one other injection of water and baking soda to flush out the gel, and within two to three months, you’ve got all your healthy sperm again."