All-in-one console.log wrapper
Just drop consolelog.js in your project and start passing data to log(). Whichever browser you're testing in, you'll see your data in the console -- if the browser doesn't have a console, Firebug Lite will load. You can pass any variable type: strings, objects, arrays, functions, etc.
Demo: http://cpatik.github.com/console.log-wrapper/
Documentation: http://patik.com/blog/complete-cross-browser-console-log/