In the old place, we used to have a Zazzle shop that sold, among other things, a t-shirt that said "Más féidir leat seo a léamh, abair liom céard is ciall leis, le do thoil! (based on my witty husband's suggestion for a tattoo!).
I never got any results from that one, but I once wore my "An Bhfuil Gaeilge Agat?" t-shirt at the Irish Cultural Center in San Francisco and was rewarded by having a woman on the elevator say "Tá neart Gaeilge agam! Is múinteoir Gaeilge mé!" As I was very much a beginner at the time, it threw me for a bit of a loop!
Redwolf