gPodder downloads free audio and video content (podcasts) for you Listen directly on your computer or on your mobile devices. If you have an android device you can follow my guide at Android Relish on Podax Podcasting & gPodder. In the guide it mentions the gPodder.net service and Podcast Directory, the desktop and mobile version can both be synced with the free gPodder.net service. The website has been unreachable once but aside from that there isn't a better place to discover and manage good podcasts.
gPodder is available for Linux, FreeBSD, Windows, Mac OS X and mobile devices like the Nokia N810, N900 and N9. Some of the highlights are that it has support for RSS, Atom, YouTube, Soundcloud, Vimeo and XSPF feeds, as well as exporting to OPML which can then be imported on an Android device. Easily synchronize between devices with full gpodder.net API support. gPodder is also easy customization with its' choice of supporting Python as it's extension language.
Homepage: http://gpodder.org/
Download: http://gpodder.org/downloads
Documentation: http://gpodder.org/documentation
Source Code: http://gpodder.org/wiki/Git
Wiki: http://wiki.gpodder.org/
Tutorial for using the gPodder.net for syncing multiple devices.