def postChunked(host, selector, fields, files):
    """
    Attempt to replace postMultipart() with nearly-identical interface.
    (The files tuple no longer requires the filename, and we only return
    the response body.) 
    Uses the urllib2_file.py originally from 
    http://fabien.seisen.org which was also drawn heavily from 
    http://code.activestate.com/recipes/146306/ .
    
    This urllib2_file.py is more desirable because of the chunked 
    uploading from a file pointer (no need to read entire file into 
    memory) and the ability to work from behind a proxy (due to its 
    basis on urllib2).
    """
    params = urllib.urlencode(fields)
    url = 'http://%s%s?%s' % (host, selector, params)
    u = urllib2.urlopen(url, files)
    result = u.read()
    [fp.close() for (key, fp) in files]
    return result