I work at Jimmy Johns too. We do all our delivery on bikes at this store. About a 4mile radius on the delivery area. I wouldn't call boulder a city, but its not really a suburb either, so a car 'might' be faster for some of the further deliveries.

As far as drinks go, I just tape the lids on, and put them inside two of the paper bags, then hold the bags with one hand while you ride. Maybe not the most effective method, but it works, and I can carry up to 6 larges or so, they just get heavy.