Right, you had a question. If you're concerned that someone else will use your trademark (the name of your show) for similar purposes, file an application for federal trademark registration. You can learn more about the process here or here. You would file in International Class 041, and your official description of services would be, "Entertainment, namely, a continuing {indicate type, e.g. variety, news, comedy} show broadcast over {indicate form(s) of broadcast medium, e.g. television, radio, internet}." T-shirts and cups would require that you would register the name in additional classes. Application fees range from $275 to $325 per class (depending on the system you use to file), so it might get pricey to file for several classes at one time. And if you're not currently using the name in connection with particular goods or services, it costs even more because you would be filing an intent-to-use application. The Dear Rich staff thinks you should take a conservative approach to filing and start with the most important class (041) and expand as your radio show gains traction.
Speaking of trademarks ... Has a trademark owner bullied you or your small business? The USPTO is soliciting comments. The TTAB Blog has the scoop (BTW, the blog's author would not approve of your use of the term "trademarked.")