you can use google reader to manage your RSS feeds which is basically how that Google Listen works. This can be done via http://www.google.com/reader/view/
Within Listen, you can go into Settings and either change the option "Audio Storage" to 10 or click the option under it to "Clear Cache" - which will delete all of them.
tried installing google listen but i loaded it and kept telling me to enable an email in the settings but i can't get to settings it closes on me after telling me that. where do i enable an email for listen?
I'm actually dissapointed in this app. Coming from the Palm Pre's PrePodder. It should be more apparent on how to download Podcasts, and which ones are downloaded.