In the US code requires shutters so you can't stick anything into the socket other than the correct plug (IIRC as of 2008?). Other responses are implying the UK (and I assume EU) now require that too.
On the other end, in India I saw a power strip that would accept EU, UK, or US plugs. I took one look and refused to get close, but someone else plugged my laptop in and it worked. (everything got 240 volts, which my laptop power supply was fine with)
No EU-regulation for that I think, it depends on the country. British Standard 1363 has had mandatory safety shutters since it was introduced in 1947 (not sure if you could still use the older British Standard 546). Here in Sweden there is a building regulation from 1988 stating outlets should be placed or designed to make it hard for children to insert things into them. I was surprised to learn that wasn't common in the US, at least until recently.
On the other end, in India I saw a power strip that would accept EU, UK, or US plugs. I took one look and refused to get close, but someone else plugged my laptop in and it worked. (everything got 240 volts, which my laptop power supply was fine with)