Registering with the US copyright office is fine, and it's pretty cheap if done online. However, there are a LOT of pages to scroll through, and it's a time consuming affair at best. Also note that it may well be 6 months or more to get any confirmation back from them on your submissions. There is a disclaimer on the US copyright office website which specifically states that you are NOT granted a copyright by submitting a request to them--that is done automatically when the work is recorded, published, or written down, etc.

To Jep...songregistration.com is a very reputable site. I did a lot of research on this stuff, and could find no negative information concerning them at all. Remember, all they do is provide a legally binding 'time stamp' for any work submitted. They do this virtually immediately, unlike the US copyright office, which usually takes months to confirm your submission, if they don't reject it for some arcane reason. Note the US copyright office will keep your money in any event...I must say that the one big advantage of the US copyright office is that you can submit and entire 'album' online for the price of a single song, so it's pretty cheap [ $35.00 online, I believe ].

The bottom line here is that however you decide to do it, PROTECT YOUR CREATIONS! There are some very talented folks posting their stuff in these forums, and it would be a crime and a shame if those great works were hijacked.

Fire, the wheel, and the I IV V -- foundations of civilization.