Song & Lyrics
On the player in the list click on which version you'd like to hear. The very first one in the list is the original. If you run your cursor down the center of the list it will scroll for more. (Keep in mind that the language versions only the chorus is sang in those languages).
(My personal favorites are the Junkie XL Mix and the Japanese version, LOL)
The Junkie XL mix of course has different beats to it, and also is the one where you can hear Avril and Luke laughing in the background during the clapping. Also during that part Avril was blowing into a beer bottle along with the music, you can definately hear it, see if you can pick it out... ;).