Shares of Apple Computer (AAPL) closed up $2.33, or 4.86%, at $50.30 in NASDAQ trading today on 21,350,328 share volume to set a new four-year high. Apple’s previous 52-week high at market close was set on October 19, 2004 at $48.35.

The new close is Apple’s highest since September 2002.

Apple’s market value now stands at $19,512,627,500 with 387,925,000 shares outstanding.

“Apple’s rise came a day after the company unveiling its new iPod Photo device, which can store and display digital picture in addition to playing music. Chief Executive Steve Jobs was joined by U2 members Bono and The Edge to show off a special edition U2 iPod at an event in San Jose, Calif.,” CBS MarketWatch reports.

NASDAQ AAPL quote here.