Apple climbed 21 slots into the top 50 of the Fortune 500 this year. How’d it get there? The company not only continues to expand its reach in existing markets, it also keeps creating new ones.Take the iPad, which showed the world the power of tablet computing when it was introduced last year. iPad 2 followed, and was one of the most highly anticipated electronic products this year. CEO Steve Jobs’ appearance at its debut in March reassured shareholders worried about his most recent medical leave. Regardless of who’s in charge, though, investors have plenty of reason to believe Apple’s magic spell on consumers can continue. —S.D.