BeyondPod supports both importing and exporting feeds. To import feeds from OPML file or a Podcast Directory tap on the "+" icon in the right side of the application toolbar. All "Import" actions will present a list of feeds available to import and allow you to import feeds into a category of your choice. (You can later assign a second category to that feed using the Edit Feed menu)
Another way to import feeds is to use your Google Reader account. This way you can
add feeds with long urls without having to type them on the device. Just add the
feed to your Google Reader account and import it from BeyondPod. To import from
Google Reader select Import from Google Reader on "Add Feed" screen
More information about Google Reader integration is available in the
Google Reader Integration section.
To export all your feeds to an OPML file, select Menu > More... > Export Feeds. BeyondPod will export all your feeds grouped by their first category (Category 1).