I've had a kegerator w/ 6' pony taps that I leave inside the kegerator. I think it would be kind of slick to have a tower or some taps in the door, but I don't want to have anything else to clean ... too much sanitation in brewing as it is! I like being able to throw the picnic/pony taps in the fridge and not worry about them - how much extra cleaning is involved with external taps?
A quick spray of Star-San up into your forward sealing faucet (Perlick, Shirron) after each serving session will keep it squeeky clean for the life of the keg. I only remove them from the shanks to clean them after a keg kicks.