The guys who turned up, had a look and then left are well rude! :-O

I think if you approach these things too seriously then it will go wrong. I once went - it was a charidee do, organised by some colleagues of one of my friends, and I was staying with her - and 80% of the people were there for a laugh, and the remaining 20% were so serious and thus boring about the whole thing.

You do need a variety of opening statements and things to ask/tell though, as it does get a bit boring when you get to the tenth person: 'So then, who do you know/where are you from/what do you do?'

I have noticed that there are speed flatmating events being held in London and Manchester - I bet they would be quite fun to go to!