Apple is reinventing the phone, Steve Jobs told an audience of 4,000 at the Macworld Expo in San Francisco on Tuesday.

After months of rumors and conjecture that have kept blogs and chat rooms ablaze with activity, Apple's CEO took the wraps off what he hopes will be the next must-have gadget -- the iPhone.

The phone is being touted as a widescreen iPod, a mobile phone, and an Internet communication device all in one. Calling it a "leapfrog" product, Jobs says it is five years ahead of any other smartphone on the market.

"This is a day I've been looking forward to for two and a half years. Every once in a while a revolutionary product comes along that changes everything," said Jobs, who cited the introduction of the Mac in 1984 and the iPod in 2001. "After today, I don't think anyone will look at these old smartphones the same way again."

The iPhone touts a new user interface that Jobs called a multi-touch display. The screen runs the length of the device, which doesn't have a built-in keypad. The 3.5-inch screen will have 160 pixels per inch for a high resolution.

Users will be able to scroll through contact lists, music lists, or movie lists with a swipe of the finger. A keypad will appear on the touch screen when needed, and then disappear when not needed. Pictures can be enlarged by making a backwards pinching motion across the screen. Want to view a horizontal picture in its entirety? Simply turn the device on its side and the picture will appear in a landscape mode.

"The problem today is the keyboards," said Jobs. "They are there whether or not you want them to be there. Controls and buttons are set in plastic so you can't change them for each application or down the road when new advances come out. We are getting rid of the buttons."

The phone, which will begin shipping in June, will run the Mac operating system and use the Safari Web browser. Jobs called software on other smartphones "baby software" and the audience of Mac fans erupted into applause and cheers when he announced that the iPhone will use the Mac OS. "It's simply got everything we need -- multi-tasking abilities, security, graphics, animation, audio, and video," he said. "It's a desktop-class application and networking."

The device will auto-synch to a PC or Mac and users can manage their rosters of movies, music, contacts, calendars, notes, and bookmarks from iTunes. Uses can set up their lists in iTunes and then synch it down to the iPhone.

The iPhone, which is only 11.6 millimeters thick, will have a 2 megapixel camera built into the back of it. Cingular is set up to be the exclusive carrier.

A 4-Gbyte version of the iPhone will sell for $499, and an 8-Gbyte version will sell for $599. It will ship in the U.S. in June and in Europe in the fourth calendar quarter of this year. It will ship in Asia in 2008. It will be sold in Apple and Cingular stores.

Here are some iPhone features: