I have used a bungee around the tiller connecter, at the center of the bar and put the bungee hooks up into the traveler track, or lacing grommets, or whatever would hold it. It really doesn't work for long though with wind and waves constantly working against you. Frankly, it is less of a hassle just to do what needs to be done and get back on course
I suppose that you could look into a cheap auto-helm at a place like Westmarine.com. My buddy used one on his Catalina 22 all the time- but that was so he could set or douse his spinnaker, slice up some cheese and open a box of crackers, open a bottle of wine- you know, stuff that "wet" sailors don't have time for.
It will still set you back a cool $400 + battery or so
That's a lot of beer