Whats great about this exploit, is that I have been using it forever... best with a fighter, or barbarian. You can get feats like cleave, great cleave, power attack, etc without actually HAVING the feat.
The trick is that when you lvl up, and are at the trainer, bring up the feat screen where you get to choose your feat, now DRAG the wanted feat to your HOTBAR..thats it.
This allows you to actually use the skill, without having the feat. although, the feat must not be greyed out when choosing.
I have a fighter, I want to shield spec him, but want some extra attacks, so I get him to where he can choose cleave/greatcleave/sap/stun/armor reduce, then drag those skills to my hotbar when at the trainer and lvling up. Now I have a fighter who can AoE, Stun, DoT, and Reduce Armor. This free's me up to choose my ACTUAL feat slot for something to boost my defense. This is also good for rogue's who want extra attacks, but need the feat slots for lockpicking/disabling. Check it out!
This works on a few other skills, but I will let you figure it out. This also works on a few enhancements too, but experiment with it, its great, and I suspect this would be fixed soon.
I hope I get some love for this one.