What You Need to Know before You Buy an iPhone
When you purchase the iPhone 4, you're supposed to activate that new iPhone in the Apple, AT&T Wireless, Best Buy, RadioShack, or Wal-Mart store where you buy the thing, just like you do with other cell phones. However, if you buy your iPhone from Apple's online store, they'll ship it to you and you activate it through iTunes, just like the old days.
When you activate the phone, you also choose your desired monthly bucket of voice minutes, SMS (Short Message Service) or text messages, and wireless data minutes right in the store.
AT&T reports that 98 percent of smartphone customers use less than 2GB of data minutes a month. Keep that in mind as you mull over AT&T's various wireless plans. It's also worth noting that these charges apply only to accessing AT&T's 3G and Edge networks and don't count when you connect via Wi-Fi in your home, office, or elsewhere.
The same two prerequisites for enjoying the iPhone have been in place since the original release — at least, for U.S. customers:
You have to become an AT&T (formerly Cingular) subscriber, unless you're already in the fold, and ink that new two-year term.
You need the latest version of iTunes software on your PC or Mac. Apple doesn't supply the software in the box, so head to Apple's iTunes page if you need to fetch a copy, or launch your current version of iTunes and then choose iTunes→Check for Updates (Mac) or Help→Check for Updates (Windows).
For the uninitiated, iTunes is the nifty Apple jukebox software that iPod owners and many other people use to manage music, videos, and more. iTunes is at the core of the iPhone because an iPod is built into the iPhone. You'll employ iTunes to synchronize a bunch of stuff on your computer and iPhone, including apps, photos, podcasts, videos, ringtones, and (of course) music.