How can I use jQuery "load" to perform a GET request with extra parameters?
Use $.param(data):
$("#output").load( "server_output.html?" + $.param({ year: 2009, country: "Canada"}));
According to the documentation you linked:
A GET request will be performed by default - but if you pass in any extra parameters in the form of an Object/Map (key/value pairs) then a POST will occur. Extra parameters passed as a string will still use a GET request.
So the simple solution is to convert your object to a string before passing it to the function. Unfortunately, the documentation doesn't specify the format the string should be in, but I would guess it would be the same as if you were generating the GET request manually.
$("#output").load( "/server_output.html?year=2009&country=Canada");