In teting this Command-# thing you mentioned, this is what I found:
In your address bar, say you have Apple.com, ehMac.ca, and uh, say slashdot.com.
Pressing command-1 jumps you to Apple.com
Pressing command-2 jumps you to ehMac.ca
Pressing command-3 jumps you to Slashdot.com
Pretty freaking cool if you ask me, but it doesn't work for links inside folders in your address bar, and I only have two links in mine that aren't in a folder. However, if you have a setup in your address bar something like this:
link1, folder, folder Link2, folder, link3
Command-1 jumps to link1
Command-2 jumps to link2
Command-3 jumps to link3
Very cool!
--PB