iPhone 3G scammers had set up Web sites posing as legitimate retailers, brokers and resellers or posted ads online at classified sites such as Craigslist. Typically, victims were asked to wire payment for the phone, which never arrived.

In the U.S., only Apple, AT&T, and Best Buy stores are authorized to sell the iPhone 3G. In the Philippines, Globe Telecoms is the only authorized store to sell the iPhone.

The Better Business Bureau advises consumers to buy iPhone 3Gs only at authorized stores and never to wire money as payment when shopping for a second-hand iPhone online.

The iPhone was released exclusively for use with Apple-designated software and with select telecom companies as the wireless provider. But hackers have figured out ways to "unlock" iPhones, enabling them to use software that isn’t authorized by Apple or to run on wireless networks other than those authorized by Apple.

Hacking into an iPhone and installing an unauthorized program are risky and could damage the product or void the warranty.

A new feature for the iPhone 3G and the new iPod Touch is the option to install applications, or apps, small programs that perform specific functions, such as tracking sports scores or enabling the use of games, that users can upload to their device.

The Apps Store in iTunes (apple.com/itunes/) is the only authorized distributor of Apps, but Web sites have cropped up promising to sell Apps at discounted prices.