It might not be a bad idea to use the ready made shirts from www.openstuff.be - I wore a formal white shirt with a Debian swirl to man the front of the booth to meet the suits^H^H^H^H customers at the Linux Expo in Birmingham.
18¤ (that's Euro if it doesn't show) and donations to Debian. He also has decent black polos with Debian swirl. And a Debian conference case, suitcase, baseball cap ... Andy
