Why not have another category of rare item (shield for example) with a built in skill? It may not need to be anything too spectacular - maybe an armor buff, a taunt or a rez sig. Either way, it would free up one skill slot on your bar (assuming you always carry some sort of rez).
This could be a very sought after type of weapon, armor or item due to it's potential in specific builds. Another option could be to go Final Fantasy 7 style and allow people to pick which skill goes into the skill slot - but I image that would introduce too many balance issues.
Just a thought.
