software recommendation - Typing tutor games with good playablity

Are there any linux typing tutor games which are enjoyable games in their own right?

I'm a computer professional, but have never learned to type properly. I also don't want my kids to pick up my bad habits! The kids are okay with TuxTyping, for a time. Something like Typing of the Dead sounds great, but is Windows only, and as far as I can tell one of a kind. I also don't want the young'uns hooked on first person shooters just yet.

So are there any quality typing games for a range of ages?