I would suggest you don't use hash 'parameters', since current support for it is buggy.
I would intercept the clicks on all links and look for a specific data- element, say, data-params:
    $('a').live('click',
        function(e) {
            var data = $(e.target).jqmData()
            globalParams = data.params !== null ? data.params : null
        }
    )
And in your HTML you can go
<a href="#map" data-params="x=4&y=2">....</a>
In this case you are creating a global variable, called params, which you should be able to access in a uniform manner from all your code.
You will have to parse those parameters yourself though, however that's not hard, could use something like this:
function getCurrentParams() {
    if (!params) {
        return null
    }
    var res = {}
    $(params.split('&')).each(
        function(i, e) {
            var pair = e.split('=')
            if (pair.length !== 2) {
                return
            }
            res[pair[0]] = pair[1]
        }
    )
    return res
}