Howdy, Folks! EJ Here.

I found a rather unique method of making a T-flip- flop. It only works if you know the secret to activating it, so it's basically a secret input.  This redstone contraption works in every version of minecraft I've tested, from 1.6.2 up through 1.8. The contraption up for download is an application of the concept. Use of the idea doesnt have to be so complicated
Downloads and videos on this page.