Folks, you got it all wrong, really!
If someone wants your shit for free, they'll get it (through torrent, Russian sites or from your player). No matter what you do.
By inserting beeps or any other shit into the music, you'll just annoy the people who just want to check your music out.
It has never hurt anyone to put up full songs in decent quality (128kbps) on their website in a player.
Don't make anyone download anything. I've skipped so often on stuff here on the forum that linked to an mp3 on mediafire that was for free download. But I just couldn't be assed to dl it, save it into a certain spot and then fire up iTunes. So I ignored the music.
Make it EASY for people to find out if they like you. Cause if they listen to your stuff on your website, the "buy" button is right next to the player (hopefully! if not, make your website better!). If you piss people off, they'll either download it from The Piratebay or - worse - simply ignore you.
Oh, and if your stuff isn't on Piratebay or mp3db.ru, then you are probably so unknown that you REALLY should give away all your music for free listening anyway ...