Why is the US also referred to as 米国?

There is a long rambling discussion here: 

http://baike.baidu.com/view/493352.htm 

and I think that you will find thousands of similar discussions on the Internet. 

It seems (according to this) that it is (1) an old term, not one invented by the Internet community, and (2) a weak transliteration thing, 米 mi sounding a bit like the Mer in America. 

There is some discussion about the 'rice' meaning of 米 and how Japan supplied rice to the US after world war II. 

It might be interesting to understand how it came to be 美国 

well, its just another more funny way of saying 美国...its used a lot in 相声 or when telling jokes,

just like that

米国 is USA in Japanese, written in Kanji. In Chinese, it's 美国.