My one pain point with this setup was when someone would recommend a specific episode of a podcast I didn't subscribe to. In order for me to listen to that episode, I would have to either download the MP3 and send it over to my phone via iTunes, stream it via Safari on my phone, or subscribe to the whole podcast in Instacast. None of those options are very convenient.
Enter Huffduffer. Huffduffer is simple genius, I don't know why I didn't use it sooner! Once you sign up for a Huffduffer account, you get your own Huffduffer feed URL. Subscribe to that feed and you're done. Now, when someone recommends a podcast episode, simply visit the episode page and click your Huffduffer bookmarklet to "huffduff" the episode. Your podcast app will receive the new episode via your Huffduffer feed subscription, sweet eh?