Apple (s aapl) is once again making an inventory tool available for prospective iPhone 3GS buyers. U.S. residents can check Apple Store stock by state, with availability updated hourly.
Unlike last year, when the iPhone 3G was in chronic short supply for weeks, by the end of business on Sunday most stores had at least some models of the iPhone 3GS. However, all stores in Alabama, Delaware, Kentucky and Utah were out of stock. Only Hawaii and South Carolina had all models in stock. As to which models were sold out most often, the list for California appears indicative of a nationwide trend.
Whether due to popularity or minimal production, the 16GB white iPhone 3GS appears to be out of stock most often, while the 16GB black model is most readily available. The 8GB iPhone 3G is available in all stores. Inventory checks are also available abroad, at least in the UK, although inventories are not updated until after closing.
Like the first weekend of sales, in which one million iPhones were sold, it appears sales of the iPhone 3GS are continuing to exceed expectations.