When my fingers started hurting often, I bought a cheap squareneck just to see if I could get the hang of it.
It's nothing like playing a standard guitar, but it's great fun and a practical hedge against the day I just can't fret anymore. And though it's mainly thought of as a bluegrass instrument, it's good for folk, rock, jazz, and blues, too. (And if you're interested in lapsteel, it's played the same way, but usually with jazzy tunings.)
If you decide to give squareneck a try, here's a little-talked-about tip: A cheap resonator guitar with upgraded cone and bridge sounds just as good as a booteek squareneck.
Even cheaper: You can buy a nut insert and put it in a standard guitar -- an easy, risk-free way way to find out whether it's for you.
And here's a final bit of encouragement from a pro: Arthritic Keith Richards says every new pain in his hands just teaches him a new way to play.