My mom has an iPhone 4s. I have a iPhone 4. The radio is out of the house. She wants to listen to Garrison Keillor. Can we get radio through our iPhones?
iPhone does not have an FM or AM tuner so you would need an accessory to tune in an over the air broadcast.
That said, a lot of radio shows can be listened to through apps or podcasts. Specifically for A Prarie Home Companion, you can use the Public Radio Player app to find your local station and listen to the live stream. Note that this uses your phone's data connection, so if you are not connected to Wi-Fi, it will use data from your data plan with your wireless carrier.
Also, Minnesota Public Radio has it's own iOS app that plays most Prairie Home Companion broadcasts when they air in the normal central US time zone slot.
The iPhone doesn't have native FM radio support, but you can use the TuneIn app, which lets you stream your local radio broadcasts on your iPhone over Wi-Fi.