You can also get it from his myspace page, but i've heard that that one is at a lower sample rate.
the page itself is amusing though. To steal slashdot's quote:
"Hi. Al here. No, really, it's Al. Seriously. What, you don't believe me? Go ahead, check weirdal.com. Hit the MySpace link. See if it brings you right back to this page. Go ahead. I'll wait. See? It's really me. I should point out... this means that conversely, all those other people on MySpace who are claiming to be me or implying that they are me... are definitely NOT me. I'm sure they're very nice people... they're just not 'Weird Al' Yankovic. I assure you."