My first apartment in Beijing was in a classy neighborhood near Chaoyang Park, with lots of children and no nearby street food presence at all. Really, when I came home in the small hours of the morning, I'd have to order McDonald's delivery if I wanted anything to eat at all.
After about a year and a half I moved to a much smaller apartment near the Worker's Stadium, where I was surrounded by lively bars and all the street food I could possibly want. There was a chuan'r guy selling grilled skewers, boiled skewers, and fried skewers of everything from cumin/chili lamb chunks to whole chili peppers. My personal favorite, though, were the jian bing stands that dotted the street in front of my apartment selling spicy crepes.
First you take the crepe batter and pour a bit on the grill.
Then you spread it into a circle with this little tool. So far this process isn't much different from ordering from a crepe stand in Paris.