In this thread I promised to release my code. It's available at geocities.com/bitzidio/lips.zip There's a little readme file in the package, explaining how to run things, but I'm here to answer any questions you may have.

I hope you don't mind but I've mirrored it here, both because I dislike geocities and because that way I'll be reminded to take a look when I get some real free time.

Thanks and cheers.