The ACTUAL laws (in the UK anyway - are as follow) :- [hope this helps mate xx]:-
1. The most common way of copyrighting anything is by placing it in an envelope addressed to yourself, taking it to the post office and posting it back to yourself. When it arrives, DON'T OPEN IT!!!!
Basically, the date stamp is evidence of when the work was created. So if somebody came along in 2008 and said he had just written a song which was copied by your friend, then he/she can prove that "the original" was really written by him/her in April 2007.
2. Try....
http://www.dulyregistered.co.uk/writers/faq £4.97 for TEN YEARS!
3.
http://www.copyrightservice.co.uk/ £35 for 5 years!
4. Or the bank will store it for you in their vault. Ask them for prices...but it's going to be a lot compared to the two companies mentioned above.