When you buy an Apple device, you're often locked in to buying other Apple products that are compatible with it. Here are five examples, and some advice on what to do. Oh, wait--there's nothing you can do.Once you enter the Big Tent of Apple, it's exceedingly hard to find the exit. Over its 33-year history, Apple has consistently elected to limit consumer choice, creating a situation known as "lock in." As soon as you start buying stuff from Apple, you'll find it difficult to move to products made by someone else without losing everything you've already paid for. Of course,...