Will the gadget — which triples as a cell phone, iPod media player and a wireless Web device — be as "revolutionary" as Apple CEO Steve Jobs has claimed?
Even if the product flops for some reason or stays limited to the high-end corner of the smart phone market, the iPhone has already jolted the industry, showing that it is not just the body and outward beauty of the handset that counts, but what's inside.
Remember the television ads for the Motorola RAZR?
The commercials showed off the sexy, thin profile of the clamshell handset and seduced more than 50 million people from 2004 to 2006 to buy it, making it the most popular cell phone ever sold.
But people want more now. There are plenty of slim, ultra-thin options out there, but not many make finding photos, saving phone contacts, picking up voice mail and selecting ringtones insanely easy.
"This is the most anticipated phone since Alexander Graham Bell did his," said Michael Gartenberg, an industry analyst at JupiterResearch. "Part of it is the fascination with Apple's products and how well they design them, but it's also about how poor the design in software is in cell phones now, and how much time Apple has spent working on this."
Apple's iPhone commercials show a finger swiping the touch screen display to activate the home menu, and with one tap on the photo icon, up pops your photos. Another icon zips over to your contacts.
Not a drop-down menu in sight.
"A few handset makers have been trying to make the phone simpler without having to refer to a manual that's 18 times the size of the phone," said Richard Doherty, president of The Envisioneering Group, a research company. "But Apple is going for the moon here."
Oakland Web programmer David Stillman, 21, hopes to be the first of his friends to own an iPhone.
Stillman, who has three Macintosh computers and two iPods, plans to trade in his 2-year-old Sanyo phone for the high-end $599 iPhone if the all-inclusive monthly charges come to less than $100. Apple and AT&T Inc. — the exclusive carrier for the iPhone — have not yet disclosed the service charges.
Consumer interest is so hot that AT&T hired 2,000 extra workers to staff its stores when the phone comes out on Friday, reports CBS News' Tony Guida.
The iPhone's screen will not be plastic but optical glass, adds Guida. And the battery will last 8 hours, not 5. That announcement alone drove Apple stock up nearly 4 percent.
Also, instead of just listening to voicemail in the order received, Apple has created what it calls "visual voicemail" for iPhone, an innovative way to see the list of voice messages so users could quickly choose the one they want to hear.
"The software is going to sell this phone — it's going to be so easy and obvious and will correct a lot of problems in other phones," said Stillman, who was waiting for Apple's flagship retail store in San Francisco to open Friday morning to do some shopping. "Other phones — even BlackBerries — can do a million things but you can't figure out how to do anything on them."
Now Apple is promoting how easy it is to surf the Web on the iPhone.
Accessing the Web from a cell phone has improved over the years as carriers have installed faster data networks, but the experience of surfing the Internet, or completing tasks like pulling up Google Maps is still not as easy as it should be, Gartenberg said.
Not many cell phones are designed to serve up the whole Web. The underlying operating system either doesn't support it, or cellular carriers have limited the access.
But cell phone makers are increasingly indicating that they want to improve the user experience and not just their hardware designs, said Jon von Tetzchner, chief executive of Opera Software ASA, a Norwegian maker of a Web browser that has versions designed for use on mobile devices.
"Apple is lifting expectations on what you can get," von Tetzchner said. "Anyone competing with them will have to match it."
The proof will come once the iPhone gets into users hands.
The all-touch screen device, which lacks a button keyboard, will force users to get accustomed to typing messages on a virtual keyboard instead of regular buttons.
The fact that it will be using a slower 2.5-generation network instead of a 3-G network might also hamper the experience of data transfers or Web access, though Gartenberg noted that it's not just the bandwidth that matters, but how well the handset's software is designed to optimize the use of the bandwidth.
Many people are already clamoring for the gadget. More than 1 million people have signed up with Apple and AT&T for more information.
Not everyone will be lining up, though, when the phones are made available on Friday at 6 p.m. local time for each time zone.
San Francisco network administrator Scott Buzzard, 31, says he's not tempted to trade in his Motorola Q — a smart phone that the iPhone will be competing with — anytime soon. He says the iPhone's price is too high, and Apple is inexperienced in the cellular market. His biggest worry is the touch screen and the software that underpins it.
"It looks cool and Apple has historically made great products, but the iPhone sounds too robust for its capacity — they're packing too much into a phone," Buzzard said while shopping at the CompUSA store in San Francisco. "I don't want to be the early adopter on an untested product."