The 2008 Sapporo Snow Festival will be held in Sapporo (of course) from February 5th until the 11th. Basically the Sapporo Snow Festival is a showcase of huge and amazing snow and ice sculptures. I have been to many festivals in Japan and can honestly say that most of them do not live up to their hype, but the Sapporo Snow Festival is one of the few that does…if you can bare the cold weather!
I actually went a few days before it started and left on the second day because it was a lot cheaper to do it that way. I suggest doing it this way not only because it is cheaper, but also because most of the big ones are (almost) done anyway and you can also see how they are made.