Hi,
I have Czech keyboard on my MacBook Pro and finally i found how to make it!!!
(no problem on Czech keyboard but i prefer U.S. for faster object insertion)
Try "Shift" and "\" (Left Shift + that key next to it on U.S. keyboard mode)
I hope this should work on your mac, i have my mac only short time and i've found the Keyboard Viewer as very usefull...
Cheers