Gigabit routers???--what's the difference, what can they do better?

-If I have a wired ethernet connection, with AT&T 6 Mbps max speed, would I get any benefit out of getting a Gigabit router?

Why is a gigabit router better? who needs one?If you're using it to network two local computers you can benefit from the speed (as long as both computers can handle the speed).