Post-it note probably a little out of my price range.... ;-)
On a serious (post it) note - I was aiming to get away from lots of bits of extraneous paper in the cockpit and the need for having to write, and rewrite things continually.
The routes I tend to do -- and just for clarification I'm talking GA pottering down to Le Touquet type flying at the minute -- are multiple legs of c.10 minutes each...so lots of heading changes, lots of routing through different airspace limitations. Be great if I could just reach up and twiddle/fiddle/push a couple of dials or buttons and there it is in front of me, rather than having to reach for the pen every few mins.
But I take the point on simplicity!