Hoping to boost sales during the holiday shopping season, Best Buy has temporarily dropped the price of the Apple iPhone 3G by $10.

The consumer electronics retailer will sell the 8-GB model for $190 and the 16-GB version for $290 until Dec. 31, a spokeswoman said in an e-mail. The deal is available in all of Best Buy's more than 1,000 U.S. stores.

Along with the price cut, Best Buy is offering an in-store "walk-out-working" service at no additional charge. The service includes e-mail setup, contact transfers from other phones, and help in learning how to use the iPhone's touch screen and other features.

Best Buy announced the promotion three days after AT&T, the exclusive wireless carrier for the Apple smartphone, started selling refurbished iPhones for $50 less than the standard price, which is $200 and $300 for the 8-GB and 16-GB models, respectively.

All the pricing listed above requires a two-year contract with AT&T.

Apple has been gradually expanding the number of outlets for the iPhone 3G since its release in July. While the original iPhone was sold only at Apple and AT&T stores, the 3G model also is available in thousands of Best Buy stores and is expected to be sold at Wal-Mart stores starting Dec. 28.

The retailer that serves millions of budget-conscious consumers reportedly plans to the sell the device for $197 and $297, depending on the model. A two-year AT&T contract also will be required.

Apple and AT&T have been making it easier for people to buy and activate the iPhone. The companies this month made it possible to buy an iPhone 3G online, have it shipped to their home or office, and plug it into iTunes to activate the service. The service is available only to new customers and current AT&T subscribers who want to add a line.

People who don't activate within a certain time frame will be charged an early-termination fee.