Ah, turns it's a problem with all python versions up to and including 2.7.  Basically a nice/clean solution for multipart form data encoding didn't make it in time for the python 2.7 release.  More details at http://bugs.python.org/issue3244

So for anyone in need with python  2.7 or older here is an example.  Download the source from http://peerit.blogspot.com/2007/07/mult … k-for.html and save it at as MultipartPostHandler.py

Then save this as a piwigo-post-example.py.  Hopefully folks don't mind 30 ish lines of code here:
#!/usr/bin/python

import MultipartPostHandler, urllib2, cookielib
import sys

(foo, url, user, password) = sys.argv

# setup cookie jar to store session cookie
cookies = cookielib.CookieJar()

#setup login
opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookies),
                                MultipartPostHandler.MultipartPostHandler)
params = { "username" : user,  "password" : password,
            "method":"pwg.session.login"}
#actually login
response = opener.open(url, params)

# when working it should look like rsp stat="ok"
print response.read()
# when working should look like Cookie pwg_id=<big hex number> for URL
print "cj=",cookies

#setup image post
params = { "method":"pwg.images.addSimple",
            "image" :open("D.jpg", "rb"),
            "category":"1",
            "tags": "testTag, Testing" }
#post image
response = opener.open(url, params)
#print response, should look like rsp stat="ok" <image_id>288</image_id><url>http://...</url>
print response.read()

Then chmod +x ./piwigo-post-example.py
./piwigo-post-example.py http://mysite.com/MyPhotos/ws.php joeuser password

Works for me, now to finish the rest of the command line sync functionality.  Thanks for the help.