I've been doing a fair bit of urban/street kiting on my Revs recently and I thought I might be able to share some tips. Feel free to chime in with what works for you.
Pick your area. Clean air isn't important, in fact it adds an element of excitement. Cars and people MUST be considered, law suits can eat up future kite purchases. Consider street lights if going out at night. Obstacles like trees, shrubs can be detrimental but signs, bike racks and playground equipment are a plus! It never hurts to have a look around before you pull any gear out.
Pick your equipment. Buildings can both cause a wind shadow and a wind funnel. Distances of free space will affect your line length.
Pick your time. Watch out for midnight watering schedules. Or even early morning deliveries.
Most importantly is to be safe about it.