Hi, Mr. Bass!
Thanks for writing, and thanks for your interest in Beam Chess. Hopefully the in-game tutorial will be enough to explain things, but in case it isn't, I've started a new thread explaining the rules in detail:
http://www.quinndunki.com/forum/index.php?topic=47.0To answer your other question, to be honest, I haven't played Khet, but judging from their website, it seems like a similar concept. Beam Chess is certainly more portable, though.

I hope I've answered your questions, and I hope you'll tell your friends about Beam Chess!