I looked into it, apparently you need a computer with the right program and hookups to program a new key. Without a master key, there was much speculation that I might need a new ECU ($!!). As it was, they needed to do some extra farting around to program new masters without the old master key. They said on some Toyotas, you need a new ECU if you lost all the master keys.
I think if I'd had a master key, I would have kept looking for a hack or shortcut to program a new one, there's got to be a way. I've heard locksmiths can do it if you have a good master.
One of these keys has a lot of burrs left on it, I'll be hitting it on a diamond wheel at the shop later. Don't need to tear up my tumblers next.