Naive... perhaps.

But the ability to text some 911-equivalent number is an option that really should be there. I'm not saying people should rely on cell phones in the wilderness, but a text message will get through when the connection is bordering impossible for voice communication.

EDIT I: On the other hand, I assume most call center operators will appreciate that they actually can ASK the caller about the missing, but vital information about their situation.
EDIT Ib: If it takes 5 SMS'es back and forth, actually speaking would be much more efficient...


EDIT II: It seems that people can send SMS to the local 911-equivalent in Sweden, Denmark and Iceland. The idea is that deaf or speaking impaired people should have an efficient way of reaching the emergency services.