OK, it's not exactly t-shirt weather. In some parts of the country, you'd have to wear two or three shirts underneath a sweater just to go outside.
In light of that, do we have a sale for you! When you buy two mental_floss t-shirts, you'll get one free. Just head over to the mental_floss store, fill up your cart, and enter the code "getonefree" before checkout.
[Fine Print: Offer good through March 3, 2010, at 11:59 pm EST. "Buy 2" applies to regularly priced shirts only; offer cannot be used on outlet items or package deals.]