We ran across this idea for creating a new floorplan and got a kick out of it. It's pretty old school, but tactile and immediate and it means less time in front of the computer. But also, we would have to make all that stuff by hand and we're a little bit lazy. So, if you've been wanting to rearrange your layout but want to see a preview before you go pushing things all around, jump below for a roundup of some great online tools to help you (and they're all free!).
Google Sketchup let's you get as into a design as you want. You can do a basic layout or you can go whole hog and design an entire room with paint colors and everything.
Arrange a Room from Better Homes and Gardens is our go-to for a quick look at a new layout. It's simple but you can't do much more than see shapes and a room.
My Virtual Home
Design my Room from Point Click Home
Image from Jack's Think Big