I've had insurance on my 3GS previously and now my 4S through my State Farm agent. $42/year for $600 worth of coverage with no deductible, and it covers EVERYTHING. Lose it, if it's stolen, if I drop it and break the screen, water damage, if I sit on it and break it...everything.
But...and I stress this...I was told that State Farm discontinued phone-specific coverage during the summer of 2010, presumably because people were abusing it leading up to the iPhone 4 launch. But, my agent says that as long as I don't let the coverage lapse (it renews every January), I can keep it for as long as I want.
However, you could try giving your insurance company a call and see if they can do anything for you. I know some people have been able to add their iPhone to their home owners insurance plan. The bad part of that is that you usually have a deductible before they'll pay out. With the plan I've got, again, there is no deductible.