Shortly after Detroit Lions kicker Jason Hanson suffered an injury in 2010 against the New York Jets, defensive tackle Ndamukong Suh was called upon to kick an extra point. Suh, who grew up playing soccer, showed off his leg to coaches during training camp and was therefore considered to be the backup kicker. Unfortunately, with a limited time to warm up, Suh clanked the kick off the right upright.
This year, the Lions luckily didn't have to deal with an injury to Hanson during a game. After their bye week he did have stitches in one of his knees, and with his status up in the air, punter Ryan Donahue tried his hand at kicking during a practice. Unfortunately, he injured himself in the process and missed the rest of the season, and Hanson turned out to be fine for the game anyway.
If a situation ever comes up again where the Lions need a new kicker in the middle of a game, perhaps quarterback Matthew Stafford could be of some help. At the NFL Experience in Indianapolis, he was bet by a friend that he couldn't kick a 40-yard field goal. He accepted the challenge and actually nailed the kick. NFL Network has video of the successful kick, as well as video of their interview with Stafford. You can check it out here.