I was in London last week and having a few minutes to spare went into the Olympic shop at Paddington station on the hunt for some tasteless fridge magnets (my friend and I always make a point of buying the most naff ones we can find for each other whenever we travel). The shop was deserted and full of those creepy mascot characters. Anyway, when I eventually went to pay, it seems you can only pay with either Visa or cash 
- if you have any other form of plastic they simply won't take it!! Fortunately my debit card is a Visa one but I can see this causing great problems. I also felt desperately sorry for the assistant behind the counter - she was incredibly polite but I can imagine it must get pretty wearing having to deal with exasperated customers who can't pay.
And Stinky, now you've said that, I can't unsee it!! That thought will now be haunting me every time I look at the logo, cos once you have seen it, it does look rather glaringly obvious.