The iPhone 4 today finally reached 24-hour availability at the online Apple Store in the US. The quicker ship dates came over four months after it first went on sale in the country and represent an unprecedented backlog for Apple, which in the past has usually cleared up the initial demand within several weeks. Boosted sales are likely to help Apple as it has already said that it's only limited by supply and has been ramping up production for much of the year.
