Popcorn Hour integrated the Mediafly engine to deliver personalized audio and video channels from podcast sources onto the device (free). See the full Mediafly experience by way of flickr slideshow here. More detailed information is below.
To launch Mediafly, go to the Popcorn Hour
On your Popcorn Hour go to home screen > Media Services > MSP
You will see the Mediafly dragonfly as shown below
You will then see your default list of channels -- your Hot Channels as shown below. Once you personalize your device (i.e. link it to your Mediafly profile) you can customize your channels by selecting specific video and/or audio shows and episodes which you want. The instant you change something on Mediafly.com it is changed on your Popcorn Hour channels (as well as your other linked devices, such as Chumby).