I've written up a preliminary OSX installation script. I believe it only works with 10.5. If anybody feels like installing YT on a 10.5 machine, this will be the preferred method as soon as I am sure the kinks are worked out:
It's not in trunk yet because until somebody else tests it and it seems okay, I'm not fully trusting.
So, if anybody feels like giving it a go ... let me know if it works!!!