I listen to OTR in many different ways and usually use the form that's the most convenient where happen to be, but my favorite way is listening to an on-line station called ABN- the Antioch Broadcasting Network. ABN is an actual licensed AM radio station in Antioch IL (somewhere between Chicago and Milwaukee near the Wisconsin boarder) even though it does broadcast it does so at very low 100mW power; which means if you live more than a mile from the station you're probably not going to receive the transmission. The station is broadcast on-line and has a small 1500 listener capacity. What I love about this station is its format. ABN motto is "Playing Today's date in history when Available!" so many of the shows originally aired "today" 50, 60, 70 years ago. So for example if it's near Christmas time you'll hear all sorts of great holiday shows. They also keep pretty similar schedule of types of shows, so a mystery block or a comedy block play everyday at certain times making it easy to catch your favorites. I listen to it on my internet radio but they have this awesome download on their site that lets you rebroadcast from your computer to an AM/FM radio in your home. I think it would be amazing to transmit and listen through an antique radio (much like the one pictured above!!!)
Go over to their site and check it out radio.macinmind.com they have schedules and players...they pay for this station through donations so if you love to listen help keep it going.