I've used this: http://blog.stevenlevithan.com/archives/parseuri
URI Parser in the past and find it simple to use and it doesn't rely on any other libraries. Its also pretty lightweight.
The author has a demo page but doesn't really explain how to use it..
Its really simple, you just do something like this:
var url = "http://my-site.com:8081/index.html?query=go&page=2";
var parsed = parseUri(url);
From there you can get things like the host/protocol/port/etc..
When dealing with the querystring you do
var page = parsed.queryKey.page;
alert(page); //alerts 2
Click the parse button on the demo page to see all properties of the parsed URI object that you can access..
jv, and where is the category and refreshRate value coming from?