What do you do when you've got money burning a hole in your pocket? If you're one of these celebrities, you find a start-up you believe in and help it pop. That's what countless celebrities including Jessica Alba, Edward Norton, Lady Gaga, and Justin Timberlake have done. Timberlake has invested in a number of start-ups over the years, but yesterday marked his most high-profile involvement yet. The singer/songwriter and SNL mainstay is an investor in the new launched Myspace, which is aiming to help musicians stay connected with their fans and showcase their music. But as we said, JT isn't the only start to shine their light and open their wallets for a fledging tech start-up. Check out the other athletes, musicians, and actors that have thrown money into new tech companies.