If you're really desiring a visit from Yogi, turn off your boombox and speak in hushed tones. Bears are not big fans of noise -- not necessarily because they prefer the idyllic, quiet life of the forest or hate rap music, but because they really don't want to be around people.
At your campsite, make your presence known. Many hikers, backpackers or simply people who aren't interested in bear-sponsored plastic surgery wear bells or loud chimes in bear country. Turn music on, scream at your campmates or yodel at the top of your lungs; anything that works to keep bears apprised of your whereabouts. Chances are, they'll be more than happy to wander far from you in search of food.
Speaking of food, let's look at how bears' appetites can cause them to seek out some friendly company around the campfire.