Or at least I've never read about or heard them from anybody else
The Power Curl: the curl's answer to the power shrug. Basically picking up a bar off the ground and curling it all in one motion. This is not an excuse to use sloppy form in the actual curl portion. Allows you to use more weight than normally, or get a few reps without throwing your hips under it and hurting your back. Also good for negatives.
Low Cable Single Handle Shrugs: Stand between two low cables with a single handle on each side. Shrug traps up and together. Gives you a really nice pump. Should probably be done last in a routine because I've never seen a weight stack that I can't shrug 20 times or more in this manner.
Also walking around the gym on your tiptoes with heavy dumbells is always fun for your calves.
Has anybody else "invented" any good exercises?