There's feedfinder:
>>> import feedfinder
>>>
>>> feedfinder.feed('scripting.com')
'http://scripting.com/rss.xml'
>>>
>>> feedfinder.feeds('scripting.com')
['http://delong.typepad.com/sdj/atom.xml',
'http://delong.typepad.com/sdj/index.rdf',
'http://delong.typepad.com/sdj/rss.xml']
>>>