I also registered just to say thank you for your work and for allowing people to try this out for free. I've learned about this software from forums at somethingawful.com - one of the biggest forums on the internet. There is a 7-page thread about this amazing engine - I'll just link it here: http://forums.somethingawful.com/showthread.php?threadid=3403902. There are many posters working in the gaming industry on that forum, so it would be great if you dropped by (registration however is not free).
I was just wondering if you tried showing this engne to NASA for example as they would be probably very interested in it. A polished version would probably end up on every physics class computer.
Good luck!