Default search language in Safari? With OS X, how do I get Safrai's location-bar search to use a particular language? This problem arises because I live in Japan but I don't want Japanese results. 

The following URL will let me do English-language searches regardless of my country:

https://www.google.com/webhp?hl=en

But how do I get Safari to do the right thing for me (search Google in English) every time?
The Safari Keyword Search extension can help you define new search engines to be used by Safari.  It can also change the default search engine Safari is using.  You could then use it to put the Google search URL as the default search.

See the instructions on the extension website.