In the UK (exclusively, I think), the sockets have gates - in [1] you'll see that there's a lever in the top hole - that pushes down the plastic covers in the bottom hole allowing the pins to be inserted. The earth plug is longer than the live and neutral plugs, meaning that you cannot electrocute yourself with a plug unless you really try. At the same time, plugs [2] typically have plastic guards around most of the pins, such that no electricity can be flowing through the pins while it's exposed.
Of course, it was all for nothing when as a kid I put a braddle or something in the top hole and then mucked around with the bottom hole. Also, I imagine that the foot injuries you get in the UK are also greater because the plugs typically face up (although I've only seen someone actually impale their foot on a holiday in America). But yes, we have the safest sockets in the world according to my old schoolteacher.
