Okay, so, like, OMG~! This is a nifty fun and also keen demonstration of a "sliding" puzzle done in Javascript. I've set it up so that admins (okay, I'm not really checking--I mean "admin" in a theoretical sense) can add new puzzles through a form. Top scores list, clues, you name it, it's here.
If we wanted to get really spiffy we could Ajax-ify this and make it two-player ... but that's for another time, I guess. And actually, I am using a bit of XMLHttpRequest goodness, since that's how the high scores are tracked. (I know, I know.)
And yes, I know you could cheat by looking at the source code. But why would you? Anyway, that's something else that could be cleaned up pretty easily if anyone wants to go all code-plumber on this.
So, go play. It's actually kinda fun ... or, if you actually know what you're doing since I haven't bothered to set up an admin interface, go add another puzzle.