The Auto Tacking Jib is an interesting contrapsion that makes single-handing a lot more do-able. It only works with a Jib or Storm Jib and Like the Jib Down Haul it is very inexpensive to build. It does not give you the best sail shape but if you are willing to give up a few 10ths of a knot so as not to have to go crazy executing a Tack or a Jibe by yourself, than give it a try.
You'll need a length of rope, two medium blocks and a good, strong shackle. There are several way to rig the shackle at the base of the mast. Some secure it to a straight track using a standing block. Some suggest using a curved track the follows the swing of the of the clue of the Jib. Mine uses a block secured to the base of the Mast.
Once you get the Jib Sheet set you can pretty much leave it alone. As you Tack or Jibe the wind just blows the Jib to the opposite side. Now I have found that in lighter air you have to ease-up on the Jib Sheet to let the Jib luff a little just before a Tack, otherwise you can be blown back against the direction of your tack. But even with that you still only have one sheet to deal with.
At the end of the 2009 Season I began working on a Jib Boom to improve the sail shape while using the Auto Tacking Jib. I'll update you with the results in the Spring of 2010.
The photo below shows the Auto Tacking Sheet in Red. You can follow it running to the bow just below the Life Line.
My next level of experimentation with this system will be to add a track and car with block to replace the block at the base of the mast.