The iPhone 4 is far from indestructible. Hell, it's starting to seem like it might actually be fragile. So here, for worrywarts and klutzes alike, is an overview of some warranty and insurance plans in case things go wrong.
Click the chart for full-size.
Lumping warranties and insurance plans together is sort of an apples and oranges type thing, but all these things fall under the umbrella of "stuff that helps keep your iPhone working." Every iPhone 4 comes with Apple's one year warranty, which covers stuff that's their fault—like manufacturing defects—but nothing that's your fault, like drops, spills and the rest. That AppleCare can be extended for a year for $69, but the stuff it covers remains the same. Best Buy offers a special plan for Best Buy-bought iPhones that, for example, covers water spillage but not water submersion, and it has no loss or theft protection. RadioShack and Walmart both rely on Apple's AppleCare protection in lieu of their own.
That's where insurance comes in. AT&T is semi-officially shilling a special plan from Asurion called MobileProtect that covers loss, theft, and water damage, for $12 a month with a deductible of $149 or $199, depending on which model you have. But moving to a third party plan from a company like Square Trade will run you much less—they have a special on for the new iPhone that buys you 2 years of coverage for $99—but they won't replace lost or stolen devices; they just fix or replace busted ones.
Of course, most of these places will try to repair your iPhone, if at all possible, before just shipping you a new one, and turnaround times all depend on what type of damage you've been hit with. But with scratches, dings, and shatters abound, it's good to know how and where to get protected. [Apple Care, MobileProtect, Square Trade, BestBuy]