Been a SquareTrade customer for awhile, at least 5 years or so. Had to process a claim twice, and both went very smoothly. For the price, I won't hesitate to buy this warranty from them for me and my wife. I bought Applecare for my iPhone 3G and have needed to use it twice already in the second year. What a great deal if you are almost certain you'll keep this iPhone for two years.
If you're considering the AmEx protection, be sure to know that there are two different warranty/protection products from them:
Purchase Protection covers dumb mistakes like getting your product stolen, or if you drop it, for up to 90 days from purchase.
Extended Warranty doubles the length of the manufacturer's warranty but keeps the same terms. So, on the day your original warranty runs out, this kicks in, but in the case of Apple products, it won't cover loss, theft, or accidental damage (technically).
It won't hurt to buy your new iPhone with an AmEx card, because either service might come in handy (especially the former), but it won't give you the comprehensive coverage (minus loss/theft) that SquareTrade offers.
SquareTrade
coupon code THIRTY30 ends up knocking down the price of this warranty to $93.75. There is some coupon already entered in their system by default to reduce the price from the normal $124 to $99, but this THIRTY30 coupon takes its place to save another $5.25.
Someone mentioned adding it as a rider to homeowners/renters insurance. I have State Farm, and my agent tells me this is not an option, for whatever reason. If you have State Farm and have this coverage on your iPhone, I'd like to find out how. Please get in touch, because of course that's a better option than any of the above...and I'd like to dig deeper!