My clowns like to eat the food right out of my fingers as I'm putting it into the water. They occasionally bump my fingers with their heads like they want to be petted, but I haven't actually tried to pet them. Recently, I've had some of the other fish start coming to eat the food from my fingers. I guess they've been watching the clowns do it and trust the "food fingers" now!
Beauregard, my cleaner shrimp always wants to clean me, but it freaks me out, so I try to avoid him, lol. ;Chicken
Let the shrimp clean you! It's a really neat experience, from the way it tickles to the pain from it ripping scabs off (I don't recommend letting it clean any scabs or wounds, but it was a significantly unique experience). My cleaner shrimp goes nuts trying to get to my hand to clean it anytime I have to reach into the tank.