I was in hospital this morning as a day patient and while waiting to be seen I picked up one of the magazines and read an interesting article. This was about a system which was originally started for hard of hearing and people with speech problems but now includes hillwalkers, hikers and anybody that may be in difficulty and doesn't have a decent mobile signal if anything goes wrong and needs urgent medical attention or the need to be rescued. From what I read, a text message needs virtually no signal compared to a voice call, so if you are in the middle of nowhere, this may save your or somebody elses life.
All you do is register your mobile as explained in the link below
http://www.emergencysms.org.uk/
I hope this is of help to you all.
Cheers Neil