Edit in JSFiddle

(function ($) {
    //jquery object擴展
    $.extend($.fn, {
        BindCheck: function (id, type, callback) {
            ///<summary>檢查有沒有重覆的id，沒有才Bind,如果沒有給id，就判斷有沒有重覆的type</summary>

            if (arguments.length == 2) {
                callback = type;
                type = id;

                if (!(this.data("events") && this.data("events")[type])) {
                    this.bind(type, callback);
                }
            } else {
                var bindCheck = $.data(this,"BindCheck") || $.data(this,"BindCheck", {})
                if (!bindCheck[id]) {
                    this.bind(type, callback);
                    bindCheck[id] = true;
                } 
            }
        }
    });
})(jQuery)

$(function(){
    $("#test1").BindCheck("click",function(){ alert(1)});    
    $("#test1").BindCheck("click",function(){ alert(2)}); 
    $("#test1").BindCheck("click",function(){ alert(3)});
    
    $("#test2").BindCheck("test2-1","click",function(){ alert(1)});    
    $("#test2").BindCheck("test2-1","click",function(){ alert(2)}); 
    $("#test2").BindCheck("test2-2","click",function(){ alert(3)}); 
    $("#test2").BindCheck("test2-2","click",function(){ alert(4)}); 
})

<input id="test1" type='button' value="test 1"/>
<input id="test2" type='button' value="test 2"/>