The above mentioned send it to yourself by mail has been suggested as "the way to obtain some sort of protection" for decades. It is even suggested on some legal sites on the web as legal. It is not now and never was. There was a time a few years back when you could send printed copy or an audio tape of one to fifteen songs to the copyright office in DC with $15.00 and some paperwork in the form of copyright application. This is no longer accepted by the Copyright office. You must now retain a lawer who specializes in the proper procedure or you can purchase a "do it yourself" kit at a good misic store to get the application and explaination and then retain a lawyer. The costs charged by the copyright office have gone up and are now per song. I cannot say exactly what the deal is right now as I have been asking around an I have found no one who has made application since the rules have changed. Three of us are shortly going to purchase the kit mentioned above to see if it is up to date. This approach was suggested by a copyright lawyer we have used in the past. He has not been informed of the details of the recent transition to make application. I know this sounds simple and doesn't help but at least you know now you are not alone in your confusion. You can still do the regestered letter to yourself for peace of mind but if you become involved in an ownership battle the court never has and will not accept this method as proof and many folks like you and I have tried. When I learn more I will repost if needed.