How can I transfer a Large (450Mb) file between two Mountain Lion Macbook Pros? I have two identical Macbook Pro Retina laptops.  How can I transfer files between them?

I have looked at the AirPort utility, but don't see a way to "create a new network" let alone make it discoverable by the other mac.

I tried enabling File Sharing, but I don't know how to tell the other mac to connect to that share (they are both on the same Wifi, where should I look for it?)

Also I tried the Bluetooth file transfer wizard but don't see the other device.

I've also tried AirDrop, but I can only send small files this way.  I have a folder with many files that adds up to 450Mb and that just times out.

What other ways should I try connecting the hosts together?
After enabling File Sharing on one machine, it will give you the name of the machine as used to connect to it. Next, go to the other computer, and open Finder.  You should see the name of the other computer in the sidebar.  If you don't, then press Go -> Connect to Server, and connect to the other machine by the name that was given in the Sharing window.

When you connect, you should see the public folder of your user account, and the Drop Box folder in there.  Copy the file to the Drop Box folder by dragging it onto the Drop Box folder.  On the target computer, open Finder, your user folder, the "Public" folder, and the "Drop Box" folder, and you will see the file that you copied.