Attached Link: http://en.wikipedia.org/wiki/BS_1363

> Quote - just the plug? or some cable? I'm trying to remember what they look like (I'm in the US). Aren't they 3 circular pins? Been a good 20 years since I graced your shores...;)

Plugs here haven't used round pins for a very long time, and while change over period was also quite long, they were pretty much out of use by the late 70s.
The only round pin plugs that show up only occasionally are the 2 pin "Europlugs" with imported items that were made for other European markets rather than for the UK.
Some old (unmodernised) houses may still have the odd round pin socket or two, but nobody but a fool would trust wiring that old (if they're still connected).