Aggie is an open source .NET-based news aggregator. It has an interesting usage for Radio Userland users:
If you are a Radio user you can use Aggie to read your news when you are away from your main computer. Radio publishes your list of news sites into a file called mySubscriptions.opml that is uploaded to your gems directory. Set the channel list to http://radio.weblogs.com/NNNNNN/gems/mySubscriptions.opml, where NNNNNNN is your Radio site number. Aggie will then use that same list of channels when it gathers the news.