If you haven't seen or used Proxi from Griffin yet, I encourage you to check it out. A quick description from the website: "The software is called Proxi and it's designed to let you configure all of your Griffin devices in one easy to use interface. Not only that, but Proxi allows you to define custom hot keys, monitor Mail, iChat, and RSS feeds, execute a repeating task, and much more."
I use Proxi for a couple of things, but my main use is to control iTunes with it. I've got three shortcuts setup to go back a track, go forward a track, and pause/play. It's awsome. I realize there are a ton of other ways to do this (including using FlyGesture!) but it's just quick and simple for me and I like it.
Anyway, I was just playing around with Proxi today and I noticed each one of the little icons for my shortcuts were customized to what the actual shortcut was:
That's cmd-control-right arrow, cmd-control-down arrow, and cmd-control-left arrow. I thought that was pretty cool and I just had to share.