Not trying to pose as fluent

I don't really want to give anyone the impression that I know more Mandarin than I do. If I say something with the appropriate tones and good consonants it sometimes leads people to believe that I actually can speak Chinese well. I can say a few things really well, usually place names that I imitate from the recorded speakers on the bus ("Shui Wan Tou Dao Le" or "Nan You Jiu Dian Dao Le") or the subway. Sometimes if I say something well, it leads a Chinese speaker to believe that I speak much more Chinese than I do, and then they try to have a conversation with me. They are quickly disappointed by my well-prounounced "Wo bu ming bai" (I do not understand).
I do answer the phone "Wei?" in such a manner that causes even my Chinese friends to make sure it is me on the phone and not some Chinese person. I am particularly proud of that. And I am trying to master this particular grunt that means "yes." Once I do that convincingly, lesson over I can move back to Pittsburgh, right?
On Sinosplice blog, John lists what different "compliments" about a foreigner's accent mean. I was particularly amused by the one about the Xinjiang. During our first two trips here, Myles and I ate lunch at the Halal restaurant fairly frequently, and we would work on vocabulary books while we waited for our food. If they weren't busy, the waitresses would come over and start quizzing us and help us with some of the tougher words. At least I can blame them for my tones being a mess (rather than my just plain ignorance and confusion over the tones).