On account of limited supply, or perhaps unprecedented demand, Apple's flagship iPhone 5s has been tough to come by. Of course, Apple has likely shipped millions of iPhone 5s units at this point, but walking into an Apple Store and picking up the exact iPhone 5s model you want still requires some patience.
As a quick example, while visiting an Apple Store in Chicago last Thursday, I was told that the only iPhone 5s model in stock was a 64 GB Space Gray model for AT&T.
All that said, Apple today brought back its in-store pickup option for the iPhone 5s. In short, folks can now purchase an iPhone 5s online and walk into a nearby Apple retail store to pick it up -- assuming of course that the desired model is in stock. Apple had previously removed the in-store pickup option six days ago, noting that interested buyers would have complete purchases in-store.
Keep in mind that many iPhone 5s models remain unavailable, but the return of in-store pickup may indicate that supply may soon be aligned with demand. An employee at the Apple Store I visited told me that they receive new iPhone 5s shipments every day, but they don't know which models they get until the package arrives. Point being, if you're still on the hunt for an iPhone 5s, keep a daily eye on Apple's online store.