When I was in Nepal back in 2000, I picked up a Khukuri - the large one that they use for beheading cows for some ritual. One clean blow, I've seen it - it's pretty amazing. Sharp as a razor, I have to put it away when I have parties at my house (well, I didn't the first one, now I have to!)
http://www.khukurihouseonline.com/Content/Catalog/Browse/ProductDetail.php?PID=ed3d2c21991e3bef5e069713af9fa6ca|5748
well that link wasn't clickable, maybe this will be:
http://shorterlink.com/?5ALRBY
one interesting feature of this blade is the half circular notch just in front of the handle on the live side of the blade, the combination of the notch and the spike jutting out from the middle of it causes the blood to drip off the blade, and not get onto your hands, both dangerous (slippery) and messy!
This site has more info and a pic of a cow losing it's head:
http://www.nepalesekhukuri.com/khukuri.html
and poking around, another pic, of a pig I think:
http://www.nepalesekhukuri.com/sacrifise.jpg 