No, not T-shirt AND underwear - but, a combo of the two. You can make your own underwear out of your old t-shirts. Just apply this pattern to your favorite, worn-out tee to make yourself a set of homemade, couture undies.
If that's not enough, there are also companies that let you personalize your own undies:
Implications - In a world where reduce, reuse and recycle has become a dominant mantra, putting this saying into practice is highly recommended for companies looking to exemplify corporate social responsibility. In order to appeal to consumers who are concerned about the environment, companies should look for their own ways to reinvent old materials into new ones instead of simply discarding them.