[shane]

I usually teach cultural difference in the language. An example is the use of 'please' and 'thank you'. In Chinese, please and thank you are not used very often, but in English, they are very important. I think that this aspect of culture is well worth teaching.

Regarding other aspects, I sometimes do it when I have classes of kids, as they like to be wowed by things that are completely different to what they are used to. I don't do it all the time though.