Just so everyone knows, QCH2002 has put a lot of work into this and I don't want to look like a buttinski by throwing a new variation into the mix at the last minute. I would recommend that everyone vote for one of the four designs currently in the poll, then any fine-tuning can be done afterwards.
Another factor to consider will be the printing costs. We may need to keep things simple just so we don't end up with a bunch of $37 T-Shirts.

It may also be possible that we could do a run of several different designs, depending on the initial setup price.
To be honest, I'd be quite happy with any of them.