Even if you don't live on an good Amtrak route, if you fly Continental this is a great card for you.  With no annual fee, you can roll points on a 1:1 basis over to Continental Airlines.  This card has no annual fee, so save the 60+ bucks you'd pay for the card issued by Continental and use this work around instead.

And if you do live in the Northeast or some other place that Amtrak is a viable option, using the points for Amtrak travel is a great option too.