Hey Bouncer, I agree with the above post about the hand smelling like the treat, also how was his hand positioned? I ask because the don't like it above them, it's better to lay the hand flat on the cage floor. My new hamster tried to bite me twice yesterday (didn't get me, I took it that it was more of a threat) a few seconds later he was sat in my hand; we have to remember that these animals are based on instinct, so you have to keep trying and keep proving you are safe.
This guide it very helpful;
Taming tips.
I'm going through the same stages as you, so I hope you keep us updated with your story! Good luck to you and Gizmo.