Kathy Sierra has a funny entry on her blog about what conference t-shirts tell you about how the organizers think about the attendees. In particular, she notes the difference between one size / men's x-large-only t-shirt conferences, and multiple size / shirts for both men and women t-shirt conferences.

It's a good parable for anyone thinking of offering their customers free promotional swag. Giving away free items that "fit" only some of your customers can send the message that you don't know or care about your other customers.

(Found via danah boyd's apophenia blog).