In the Mail message list, hold down the Option key, and then also hold the up or down arrow keys for more than a second, and there ya go: top or bottom of the list. It's a very weird interface detail; I don't know of any other Apple app that requires a key held down for a period of time before it does its thing. But at least it works. (I don't know if it works in Panther Mail.)
P.S. I'd love to see something like Type Select back in Mail, or if someone can suggest how to get the bundle to work again, I'd appreciate it...

