I was In Tijuana for a birthday party of a friend.
I told the USCBP guy at San Ysidro I went to a mexican birthday party for the first time and he asked how I liked the part, what I thought of it, whether or not I hit the pinata (I mentioned there was a pinata)
When Entering Tijuana by foot through the new customs and immigration inspection building on the Mexican side, the INM women thought P was part of my last name, since she saw the field Type=P (document type field in american passports)
I thought it was funny she didn't know what the type field was.
At the same time, there was a group of chinese tourists entering Tijuana by foot; the mexican immigration officials took their passports to one desk, filled out their immigration forms, called people up, and said in broken chinese, Qian Ming (Sign your name)
It was a funny process.