Paul Levy has some smart things to say about "icebreakers" for workshops in his comment to this: Energisers for Introverts.

Just as "ice breakers" make the dangerous (and often wrong) assumption that there is "ice" at the start of a workshop that somehow needs to be broken, the idea that a workshop needs "energising" at the beginning is also a bit sweeping and often mistaken too...

I prefer to look into the creativity field and find the concept of "flow". Flow is better when it is not manipulated by a facilitator (no matter how well intentioned). Flow happens differently in different people..