I'm near the end of A Jester game, and I have to say, the Jester is waaaaay cool.
Three words
Use any item.
I gave him the helm of Valior early on, so simulcrum (double enhanced Bards song) means the lowest AC of any party member is around -18. His own hangs around -24.
Druids staff, Staff of the magi, Paladins bracers, Psions Blade. Yep can use them all. Lots of fun. A roleplaying blast.
Now yes I know a thief can get the same ability, but what use is a normally mage only item that increases spell numbers? The full gamut is of avail to the Bard.