Mac: You can get plenty of podcasting apps for your iDevices, but what about your Mac? Popular iOS app Instacast now has a Mac version in beta, bringing its solid feature set to the desktop along with sync across all your device.
If you use Instacast for iOS, everything you expect will be there: subscriptions, show notes and playlists, but the Mac version also adds a few new features. You can donate to your favourite podcasts using Flattr, actually download in the background (something iOS mostly prohibits), use the controls on your headset remote and stream via AirPlay.
What's most notable is Instacast's sync functionality. Not only will it keep all your podcasts updated on every Mac and iDevice you have, but it will push any files downloaded on your Mac directly to the iDevice's rather than pulling them for the internet. This means you won't have to wait quite so long to update all your podcasts, which can make a big difference when you're rushing out the door and want something to listen to during a long car ride.
You can download a beta version of Instacast for Mac for free if you want to give it a try. We found a few bugs, but all were minor, such as the delete shortcut not working when deleting a playlist. If you're interested in syncing functionality, you'll need to pay $5.49 for the iOS version.