Laptop working again
HUZZAH! My laptop is *not* broken, as I thought it was! I checked with a Toshiba dealer to see how much it would cost to replace the keyboard, and the guy suggested I just try to re-seat it. That it might just have come loose or got some dust in the connectors. So, with a little direction from the Toshiba guy, I was able to take the laptop apart without destroying it, and the keyboard started working again.
The downside is that I have no reason to buy that Portege 3500 tablet PC I wanted.