Pent-up demand for the iPhone 3G is manifesting itself on auction site eBay, where eager buyers are bidding in excess of US$1,000 to get what's turning out to be a hot commodity.

The demand for the iPhone remains high even off the Internet, with lines forming Monday outside an Apple store in New York to buy the limited stock of the devices.

Launched on July 11, the phone sold more than 1 million units worldwide over the first weekend, according to analysts. The demand has continued with carriers, including AT&T in the U.S. and O2 in the U.K., reporting iPhone 3G shortages. The 16G-byte iPhone is priced at US$299 in the U.S., with the 8G-byte version priced at US$199. In some countries carriers are giving the iPhone for free with contracts.

The bidding for a 16G-byte iPhone 3G on eBay is exceeding US$1,000, with one bid ending at US$2,325. The average 8G-byte iPhone 3G bid is reaching the US$800 to US$900 range.

In one auction a potential bidder asked if the iPhone could be shipped to Indonesia, indicating that bids were coming from countries where the iPhone won't be shipped by the end of this year. The phone is currently sold in 20 countries, but Apple hopes to expand its availability to 70 countries by year-end.

The sellers are advertising the iPhones as "unlocked" to work with any carrier, also providing a link to a recent hack issued to unlock the iPhone.

Apple did not supply enough devices at this year's launch, creating a demand. During last year's launch of the first-generation iPhone the company sold 270,000 handsets.

Supplies should normalize over the quarter and the iPhone 3G is set for long-term success, said Mike Abramsky, of RBC Capital Markets, in a report. The company could ship up to 5.1 million iPhones in the quarter.

(Elizabeth Montalbano of the IDG News Service in New York contributed to this story.)