jQuery: serialize() form and other parameters

Alternatively you could use form.serialize() with $.param(object) if you store your params in some object variable. The usage would be:

var data = form.serialize() + '&' + $.param(object)

See http://api.jquery.com/jQuery.param for further reference.

serialize() effectively turns the form values into a valid querystring, as such you can simply append to the string:

$.ajax({
    type : 'POST',
    url : 'url',
    data : $('#form').serialize() + "&par1=1&par2=2&par3=232"
}