It used to be uncouth to be slurping and smacking when you ate. Now it seems like everyone is a gross hog, not just the foreigners.
Well, in all fairness, etiquette can be slippery. In certain cultures, particularly in Asia, slurping ranges from acceptable to expected -- the same being true for burping, smacking lips etc.
This reminds me: if you like this topic, check
Tampopo -
http://www.imdb.com/title/tt0092048/It's a japanese love letter to food, cooking & eating. There's all sorts of stories interwoven in a bigger story, and lots of food. It's pretty cool and always leaves me with the cravings, which is also nice.