Coffee Shop Characters

Maybe I'm a little too inspired by Jarmusch's interesting Coffee and Cigarettes vignettes of quirky characters in coffee shops, but I'm wondering what it would be like to work in a coffee shop for a few days. There is no other job in society which caters to a clientèle that suffers from a dire physical craving for an addictive drug. I assume that the types of people one encounters when working in such an environment are quite wide-ranging and fascinating. You'll have the half-asleep zombies who drag themselves in looking for a boost, the over-caffed hyperactives who wrongly assume that another cup might cure the shakes that the previous 7 caused, or even the quiet artist who simply enjoys the atmosphere of coffee shops (maybe for the same reason that I would enjoy studying its customers). The only parallel work environment to this might be working in a liquor store, although from what I know, it's quite rare to get complete drunks walking in (or, if so, it's a rare occurrance, and grounds for not selling alcohol to the person). In a coffee shop, a large portion of the customers will be under the effects of a drug, and those who are not are seeking a quick fix for a variety of reasons. The relationships between these people would be interesting to study from a sociological perspective -- though not in the way that Jarmusch did it -- in order to look at the broader effects of drug consumption and purchasing.