I guess this duet thing got under my skin a little...found numerous fantastic duets by Rita Coolidge & Kris Kristofferson, with this one from "The Muppet Show" being my fave:
http://www.youtube.com/watch?v=3Ziuht6Py4Y

This version of "Loving Arms" is also great - I never thought I'd apply the adjective, 'sweet', to a performance by Mr. Kristofferson...
http://www.youtube.com/watch?v=mdBu1ovw54o

Along the lines of very pleasant surprises, Kris singing "Guess Things Happen That Way" with Norah Jones - and it's great!
http://www.youtube.com/watch?v=FwFcmPwYyr4

Norah & Willie take on "The Wurlitzer Prize"
http://www.youtube.com/watch?v=pU9hWiYjVTY