Out of turn powers work too.
Yeah, you got it, Spiff.
If he wants to use any other power than his base power on his turn, he loses the cycle. Makes for very interesting choices! 
Here's what I'm going to use to track this:
It has two dials to show which form you chose this turn (top) and what form you chose last turn (bottom). When your turn's over, you clear the "chosen last turn" dial (one of the choices on the dial is blank) and rotate the tracker so that your current choice (the top dial) becomes your previous choice (the bottom dial). Rinse and repeat.
It's card sized for easy storage and will look good sitting next to your other cards on the table. It lamentably uses placeholder art because... you know why, but I'll update that to the good stuff if/when I ever get it.
I'll have the PDF file up on http://www.spiffworld.com/sotm/printable.cfm in just a couple of minutes.
That is awesome! Thanks for making and sharing it, Spiff. 
Some days that's the only way to get anything done 
Platypus form rocks!
And mnay Thanks Spiff for the Tracker!
The way I was thinking of doing a tracker is to have three double-sided tokens for each form, with one side saying “last turn.” The wheels are a great idea, too: I guess you must have lots of templates for wheels, Spiff!
P.S., I grabbed an Aim token out of my Tactics box to represent the object of Jim’s True Purpose!
Ha! That's awesome. 
I actually have a collection of glass beads, dice, etc. with my Sentinels stuff that I use for stuff like this. Comes in handy for a lot of situations…
Clever, clever... You'd need like 2 of them, though, to allow for out of turn powers. Unless you want to just tell them to turn it sideways if they use the power an additional time.
You got it, I love spinners. They don't take much table space and they're hard to screw up with a misplaced table bump. Plus, they're fun to build, which is half the attraction for me. 