Another thing that I have found that helps avoid breaking the mood of the roleplaying when you run a skill challenge is simply not to tell the pcs that they're in one. Have them roleplay, ask for appropriate skill checks at the right moments, track successes and failures and consequences and award xp at the end. This technique has turned skill challenges from a corny gamist thing that interferes with the narrative of the game to a seemless insertion of mechanics into a flowing story and roleplaying moment, at least for my group. Also, my more observant players will eventually pick up on the fact that they're in a skill challenge, but now they look forward to them as opposed to deriding them as lame.