With feature phones it was possible to dial <emergency> by feel, without removing the phone from my pocket (or making it obvious what I was doing). I'd love to be able to fire off an emergency SMS without having to expose my phone or having to use the touch screen.

In my head I'd love to be able to morse-code SOS on the volume keys as a trigger. Possibly once on the v-down, phone vibrates and then again on the up to stop accidents.

I wonder if the UK can accept SMS messages on it's 999 or 111 service... love the app though :)