Uncle Rod's Boot Camp

Here is a link to a somewhat different approach to learning to play the uke.  This Hawaiian wants you to learn to do all the open string positions first, in all the keys that fit the ukulele.  He recommends that you play each worksheet, slowly at first, building up speed as your muscle memory comes into play.  First with 4 beats per chord, then three, then two then one, as skills improve.

Mary has been using these sheets, along with a metronome, for some time and recommends them.

Now this won't give you anything on movable chords or using all the fretboard, but it is a great start.

http://files.meetup.com/2287271/ukulele%20boot%20camp%20rev%5B2%5D.pdf