I think it depends who you know
I see loads of users in London on public transport, for example... Last time I was on the tube I was comparing the number of visible iPod users compared with the number of BB users in a carriage. 3x BB users inc myself. All those business types going to work in the City I suppose. 8 or 9 I could spot with iPods.
Also 'fun' to play 'spot the operator'. T-Mobile is blue, Vodafone is black, Orange is black but has their orange logo, etc...