This is indeed a single worth listening to a second time.
I have this on a Nancy Sinatra cd comp. and last week this track came up on my i-pod shuffle. Hadn't listened to this track for years or really listened to it properly.
But listening with the earphones on I was well impressed with the way the repeating of the lines of the lyrics are sung by Nancy and Lee.
Pete Smith describes it much better than I could on his "lost vinyl gems of the 60s" blog.
To quote "capscatty", one of the 890 comments on youtube,
"This sounds like Johnny Cash and June Carter on acid"
That's a compliment by the way.