Insurance packages from carriers are rarely good value and often a complete rip-off.
For example, in the UK, O2 offer insurance on the iPhone at the following ridiculous rates for the 32GB iPhone 4:
£15 a month monthly premium and the following excess (deductible): £100 for first claim, £125 for second claim and £150 for third claim.
Bearing in mind that Apple will give you a swap out for a damaged phone (including water damage) for £139, losing money with this insurance is a guaranteed certainty:
If you break it once, you'll pay £280 on O2 (12x15 premium + £100 excess), compared to £139 just swapping it out. If you break it twice, you'll pay £405 compared to £278 and if you break it 3 times you're paying £555 with O2 insurance compared to £417 at an Apple store for a swap out each time. Of course, if you don't break it you'll pay £180 for the insurance compared to nothing if you don't insure it
The O2 insurance does also cover loss or theft (but not unattended theft), but most household insurance will give you that for a very small premium (around £10 a year)
This has got to be quite simply the worst "insurance" policy in the history of insurance policies: I've never seen one that under absolutely no circumstances do you come out better off than if you didn't have it!