We are currently working on some designs for the shirts. If you would like to see what we have come up with, visit this page.
If you would like to comment on a design (or have a design of your own) send an email to firstname.lastname@example.org. The pricing we are looking at is around $15. If you think you might be interested in a shirt, please send an email to the address above. We are just trying to see what kind of interest there is right now, we will take official orders once the design has been confirmed.
If you are submitting a design, please ensure it doesn't infringe on anyone's copyrights. The last thing we want to do is deal with lawyers because of a few t-shirts! In some cases (BSD daemon?), the permission can be obtained just by asking.