I use gReader, which allows me to subscribe to other feeds that 'Listen' can't seem to find through searches, or are non-podcast RSS like the Android Central site so that I can get the newest updates without having to always go to the site through my internet browser.
On another note, does anyone know of an audio player that can be used instead of the default? When I do play a podcast through gReader, it streams using the default player, but you can't turn the screen off or hit the power button. You can hit 'menu' and the screen will go blank, but if you accidentally tap the screen while putting it in your pocket (while listening), it can end up pausing or re-starting it, which can be frustrating.
I'd like to be able to hit the power button to blank out the screen (so I can put the phone in my pocket while listening), yet allow the podcast to keep running and not turn the screen back on if you accidentally touch it.