There are some spells out there which get a charge count without being on a recharge timer, I was thinking it would be nice to be able to use the segmented bar to display the charges.
The initial spell which made me think about this was:
http://www.wowhead.com/spell=112965/fingers-of-frost
But since then I've also found another!

I've, now, noticed the big difference between these and the recharge implementation is that these are buffs!
Which is cool as that means we can track a CD underneath them.

Bonus points for being able to colour the different segments of the bar individually.
My thinking here being that it's easier to tell at a glance, or with peripheral vision, when you're at max stacks and you should use one so you don't waste the next charge.

I could make a dodgy paint picture up if you'd like but I think you know what I mean.