I was recently working on a ASP.NET RIA which has a web form with the input field in which users can type some search term and press the search button or hit enter key. Search is invoked by an asynchronous call and done on the server. The text field is placed inside of form tag and because of that, when someone hits the enter key, instead of the desired behavior (asynchronous call), the whole form is submitted to the server. There is more then one possible solution for this kind of problem, but because I was already using jQuery for building the whole application's UI, I fixed the problem with the following elegant jQuery's cross-browser code snippet:

     $(document).ready(function() {
         $("form").bind("keypress", function(e) {
             if (e.keyCode == 13) {
                 search($("#searchTerm").attr('value'));
                 return false;
            }
         });
     });