Looks like it's Christmas in July. The hottest gadget on the market now, the iPhone 3G is in such high demand that many stores around the nation simply can't keep up. The portable communications device has so far sold out in 21 states, according to Fortune.

Fortune says that states reporting no more iPhone 3Gs in stock are "Connecticut, Delaware, Hawaii, Indiana, Iowa, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Missouri, Nebraska, New Hampshire, New Jersey, New Mexico, Oregon, Rhode Island, Tennessee, Utah, Washington, and Wisconsin."

Apple warns consumers that more shipments of the device are on the way, and that it is wise to check an Apple Store at 9 p.m. the night before for availability. Apple also advises people to get up early the next morning to ensure the best chance of getting an iPhone 3G. Earlier today, the software giant reported it sold its one millionth iPhone on Sunday.