With the exception of painting faces, wearing foam fingers, and lighting brush fires in the shape of mascots, the best way to signal allegiance to a favorite sports club is to wear a logoed T-shirt. Proclaim your team preference with today's Groupon: for $15, you get $30 worth of Boston sports apparel and novelty items from I Love Boston Sports.

The super fans at I Love Boston Sports stock their virtual shelves with T-shirts and novelty items, many designed by the artists at The Boston Sports Apparel Company, that show support for Boston's home teams with wit and style. The Fantastic 5 shirt ($19.99) comes emblazoned with hoopsters rendered in comic-book style, and the I Hate NY! shirt ($19.99) exhibits distaste for the Empire State more effectively than giving the Statue of Liberty a wedgie. A red Gameday baseball raglan tee snuggles men and women's torsos in ring-spun cotton printed with Boston affection ($27.99). The Boston Tea Party banner lightheartedly displays one's home-team loyalty ($59.99), and a similar Boston Tea Party mousepad ($9.99) helps computer mice to glide softly and real mice to wrestle freely without danger of head injury.