The most interesting types of big and tall shirts that I have found are specialized big and tall travel shirts.  Many of these big and tall travel shirts have special features such as sun protection made from a fabric rated for its level of ultraviolet or UV protection.  Other big and tall travel shirts have insect repellant built into the shirt- so you can enjoy the outdoors without being bothered by pesky bugs.  There are also big and tall shirts made with unique fabrics that keep you cool as they whisk moisture away from you, so you can arrive at your destination fresh smelling and dry.  Some big and tall shirts on the market are made especially for those who enjoy outdoor sports such as fishing shirts with extra pockets for all of your fishing gear.  Big and tall shirts are most prevalent on the Internet, as many of the retail stores do not carry big and tall shirts.