Steve Jobs, the chief executive of Apple, has delivered on the hopes for the next generation of iPhone: cheaper, faster, and more enterprise-friendly.

The new phone, which will go on sale July 11 in 22 countries, will run off the 3G network, which Jobs said would enable the phone to work 2.8 times faster than it does with the current E.D.G.E. technology.

Pictures of the new gadget displayed at Apple's annual conference on Monday show it to be even thinner, with a black plastic back, solid metal buttons, and the same display and camera. The announcement that the new device would have a flush headphone jack and dramatically improved audio was greeted by roaring applause.

In addition to 3G support, Jobs cited affordability as a second major concern for Apple. The 8-GB iPhone 3G will retail around the world for $199—that's $400 cheaper than the original iPhone, which made its debut a year ago—and $200 cheaper than the current price.

Jobs also said that a 16-GB version will be available for $299, and will come in black as well as white.

The 3G iPhone, which Apple is hoping will effectively compete with Research in Motion's latest BlackBerry offerings, will also have G.P.S. functionality and enhanced battery life; the device can now hold 300 hours of standby, five hours of 3G talk-time, seven hours of video, and 24 hours of audio.

Before Jobs unveiled the device itself, around 11:30 a.m. Pacific Time, he and fellow presenters spoke extensively about the new iPhone 2.0 software, which will also become available to the general public at the beginning of July.

The new software will enable the iPhone to support corporate email accounts (as R.I.M.'s BlackBerry and Palm's Treo already do), as well as a wide variety of add-on applications from third-party sources like the Associated Press, Pangea, and Major League Baseball.

Another major innovation unveiled by Apple today is a new platform for .mac users called "MobileMe," a "push" technology that will allow for automatic loading and syncing of mail, address book, and calendar items on the device—making its mail functionality much more similar to that of a Treo or BlackBerry.