Here’s the the question: you can charge an iPhone with any AC-to-USB adapter. So how does Apple get off charging $29 for theirs? Ken Shirriff took one completely apart to figure it out, and it turns out, Apple’s charger goes above and beyond what’s needed–it’s legitimately more complex and sturdier and more capable than other chargers. Upgrades include “super-strong AC prongs, and the complex over-temperature / over-voltage shutdown circuit,” as well as a bunch of hardware designed to keep electromagnetic interference to a minimum. Of course, the added hardware probably costs a dollar, and Apple sells it for $20 more than competitors, but still! Teardowns: so useful! [via @mattbuchanan]