So maybe not totally useless certainly fun. Normally, ruby scripts are finished when you reach the end of a file; however, this is not always the case. You can end your script sooner by using the __END__ keyword in your script. Once added, everything you type after that will not be parsed by ruby.
So what?
Well, you can use the global variable DATA to get the contents of what you wrote after the __END__ block. DATA is actually a File object to just that piece of text in your script.