My first attempt at a bookmarklet. A simple one which inserts the current date on a page.

date bookmarklet.js

javascript: (function(){
  alert("Hello?!");
  var today = new Date();
  var day = today.getDate();
  var month = today.getMonth() + 1; 
  /* January starts with zero */
  
  var year  = today.getFullYear();
  var thisDate = month + '/' + day + '/' + year;
  alert(thisDate);
  document.write(thisDate);
}());
/* I previously used the other comment style, which broke the bookmarklet */