Pat,
For starters, how about the 1st and 18th at the Old Course?
Also, and this is just a guess, in a trditional "out and back" links routing, the fairways of the front 9 could join those on the back as well as share green sites.
Since our planned trip to Sand Valley was rained out yesterday, we played 36 at Shoreacres. The 9th hole is now VERY easy since it joined FWs with 18. You can flair it right all day and still have a simple approach of less than 150 yards to a relatively flat and benign green.
ZERO impact on pace of play.
Our home course originally had shared FWs on 8/9 and 15/16. Perhaps we will return to that someday.
Cheers,
Ian