How safe is your hotel room?

I've heard many people lament about the loss of the old fashioned hotel room key - you know, like the one you use in your house. Of course, those get lost and are difficult to replace, so hotels have switched to electronic keys.

Those keys are problematic and annoying. It seems they constantly get erased or your door is recoded. At a DefCon conference a few years ago, I was sharing a room with 2 other people. Inevitably, one person's key would stop working - they would go to the front desk and get 3 new keys, but then couldn't find me. Then my key wouldn't work, rinse, and repeat.

But, now it seems that the manufacturers of these devices have put a too simple administrative interface on the actual doors that allow ne'er-do-wells access to your room.

Something to think about while traveling.