My mobile phone's got this feature which gives you a 5-10 second warning if there's going to be an earthquake of magnitude 5.0 or over nearby. Doesn't sound like much but can make all the difference.
They don't promise they can always get you the warning before the shaking starts but it's a lot better than nothing. I got this phone in mid-2009 and the first two pics show all thrteen warnings I've had since then. Ten of them have come since last Friday 11th, the last one about six hours ago.
The first characters tell you which prefecture the earthquake's epicentre is expected in, and the last pic shows the message itself which basically says in this case, "An earthquake has started in Nagano-prefecture, prepare for strong tremors".
The thing is that I didn't get anything last Friday at 14:45 when before the building started rolling. The first warning I got on March 11th was at 19:36 when I was halfway home.