I don't know about this. To be honest, I would avoid any sort of quick and easy route. You are more than likely not going to run into any huge problems with your works, however; if you are going to do it, do it right. Here is a link to the US Copyright Office's website to where you can get this done legally and have it be done. Also, join ASCAP or BMI as well; as that will secure that you make any money that is generated from your songs by way of any placement (in films, TV, video games, etc.) that is receives. I know this all sounds a little complicated, so feel free to ask any more questions you may have.

http://www.copyright.gov/