Back during 9/11, New York’s phone system was crippled, so I had only sporadic access to the Internet; I could get online for a few minutes, but would often get bumped off. To quickly let my Canadian friends know I was alive, I sent an email to one well-connected friend in Toronto and asked him to forward to everyone I knew up there. These days, texting is an even faster way to let loved ones know you haven’t been killed in a recent terrorist attack. But it has the same one-to-many problem: In a crisis, it’s too laborious to to send message to dozens of people.

Thus was born the idea for textOK, a new service in Britain that works like this: You sign up at the textOK web site and input a big list of every phone number you’d like to contact in an emergency. When the next car bomb goes off in downtown London, you just send an SMS to textOK’s number — 60999 — and the service will bulk-blast a message to your posse telling them you’re still alive. It costs 25p, which apparently will be donated to charity.

Perhaps most intriguingly, textOK argues that their service has positive network effects:

Keeps the phone network alive — lots of people sending 1 text message through us instead of making phone calls will drastically reduce the amount of network traffic.

(Thanks to Engadget for this one!)