Unless you've got cat5e or cat6 cables I don't think the gigabit switch will do you all that much good. Probably a waste of $$. A 10/100 switch will do the job just fine for quite a bit less. Unless you're moving large files across your house, you're still going gigabit to a 10/100 uplink port on the router, so it's pretty useless.
The uplink port will let you stack the switch and the router. Just make sure the switch is just a switch, or it won't work. I've known quite a few people that used up their 4 ports on their routers, and went out and bought another router. That can cause problems. Most off the shelf, residential use switches won't even need an IP assigned, and everything plugged into it will grab DHCP from the router.