Another comment about the food, in 11 of the last 12 days I had sessions at night, they would start around 7-8 pm, to allow time to get to the venues and get thru security you would leave about 1 1/2 hours before the start, so you didn't really have time for dinner before the event, because you couldn't take any food or drinks in, you had to rely on the crappy food that they sold there, other than small sauages ort of grilled and not all places had them, you were getting preprocessed food, like buns or a chinese sort of small hotdog, I remember one night I was really hungry but they didn't have much, so dinner consisted of a snickers, ice cream, bun & a zero coke (really healthy), at the main area near the Aquatics centre & Birds Nest there was a McDonalds, no other Franchises.
I did discover a Subway at a shopping centre, but I had to go out my way to buy a roll there, but I did have a local bakery, which did really nice cakes, buns, rolls & some very small pizzas, so I did buy some of that on the way home from early sessions or for lunch when I had the afternoon off.
I do hope London can sort that out, I mean it seems ironic that you can't sell healthy foods at sporting events, I mean what can a supporter do without his meat pie or box of greasy chips. At least at Athens you were not far from shops & resteraunts to eat (I had my life time quota of Suvlaki)
I think when Beijing did their test events they didn't have too many foreigners at them.