Very nice Bob! I've got a few 'peanut' slaves in my bag and they are handy, but I think I'll have to build one of yours to play with. I like the idea of being able to trip two flashes simultaneously, without needing two slaves.
If you want to see pricey accessories, check out the Pocket Wizards. They are professional level radio slaves, and will take a big bite out of your wallet.

Thanks for sharing this,

Jerry.