JQuery Event for user pressing enter in a textbox?

   $('#textbox').on('keypress', function (e) {
         if(e.which === 13){

            //Disable textbox to prevent multiple submit
            $(this).attr("disabled", "disabled");

            //Do Stuff, submit, etc..

            //Enable the textbox again if needed.
            $(this).removeAttr("disabled");
         }
   });

You can wire up your own custom event

$('textarea').bind("enterKey",function(e){
   //do stuff here
});
$('textarea').keyup(function(e){
    if(e.keyCode == 13)
    {
        $(this).trigger("enterKey");
    }
});

http://jsfiddle.net/x7HVQ/

Here is a plugin for you: (Fiddle: http://jsfiddle.net/maniator/CjrJ7/)

$.fn.pressEnter = function(fn) {  

    return this.each(function() {  
        $(this).bind('enterPress', fn);
        $(this).keyup(function(e){
            if(e.keyCode == 13)
            {
              $(this).trigger("enterPress");
            }
        })
    });  
 }; 

//use it:
$('textarea').pressEnter(function(){alert('here')})