Given below are some useful Jquery snippets. Hope you find it useful.

//Check All or Uncheck All

 
$("#chkAll").toggle(
    function() {
        $("input[@type='checkbox']").not('#chkAll').each(function() {
            this.checked = true;
                });
       },
    function() {
        $("input[@type='checkbox']").not('#chkAll').each(function() {
          this.checked = false;
    });
    });
});

//checking if a checkbox is checked

 $('#edit-checkbox-id').is(':checked');

//Hover

 $("#ID").hover(function () {
      // do mouse over something
 }, 
 function () {
      // do mouse out  something
 });

//Dynamically adding target attributes for all anchor links except our domain

  $("a[href^=http://]").not("a[href^=http://www.yourdomain]").attr("target", "blank");

I would share some more in my next blog entry.

Happy Scripting!!!

Cheers,
Raja