post = urllib.urlencode({'profile_background_color':'#FF00FF',
                         'profile_text_color':'#F00000',
                         'profile_link_color':'#FF0000',
                         'profile_sidebar_fill_color':'#FFF000',
                         'profile_sidebar_border_color':'#FFFF00'})

--разделитель
Content-Disposition: form-data; name="_method"

put
--разделитель
Content-Disposition: form-data; name="authenticity_token"

60006ee9827f3fd786eb07cb6dfda8176d19aa62
--разделитель
Content-Disposition: form-data; name="profile_image[uploaded_data]"; filename="image.gif"
Content-Type: image/gif

тело файла "image.gif"
--разделитель
Content-Disposition: form-data; name="user[name]"

my_name
--разделитель
Content-Disposition: form-data; name="user[location]"


--разделитель
Content-Disposition: form-data; name="user[url]"

http://bla-bla.ru
--разделитель
Content-Disposition: form-data; name="user[description]"


--разделитель
Content-Disposition: form-data; name="commit"

Save
--разделитель

urllib2.Request(host, post, headers)

import itertools
import mimetools
import mimetypes
from cStringIO import StringIO
import urllib
import urllib2

class MultiPartForm(object):
    """Accumulate the data to be used when posting a form."""

    def __init__(self):
        self.form_fields = []
        self.files = []
        self.boundary = mimetools.choose_boundary()
        return

    def get_content_type(self):
        return 'multipart/form-data; boundary=%s' % self.boundary

    def add_field(self, name, value):
        """Add a simple field to the form data."""
        self.form_fields.append((name, value))
        return

    def add_file(self, fieldname, filename, fileHandle, mimetype=None):
        """Add a file to be uploaded."""
        body = fileHandle.read()
        if mimetype is None:
            mimetype = mimetypes.guess_type(filename)[0] or 'application/octet-stream'
        self.files.append((fieldname, filename, mimetype, body))
        return

    def __str__(self):
        """Return a string representing the form data, including attached files."""
        # Build a list of lists, each containing "lines" of the
        # request.  Each part is separated by a boundary string.
        # Once the list is built, return a string where each
        # line is separated by '\r\n'.
        parts = []
        part_boundary = '--' + self.boundary

        # Add the form fields
        parts.extend(
            [ part_boundary,
              'Content-Disposition: form-data; name="%s"' % name,
              '',
              value,
            ]
            for name, value in self.form_fields
            )

        # Add the files to upload
        parts.extend(
            [ part_boundary,
              'Content-Disposition: file; name="%s"; filename="%s"' % \
                 (field_name, filename),
              'Content-Type: %s' % content_type,
              '',
              body,
            ]
            for field_name, filename, content_type, body in self.files
            )

        # Flatten the list and add closing boundary marker,
        # then return CR+LF separated data
        flattened = list(itertools.chain(*parts))
        flattened.append('--' + self.boundary + '--')
        flattened.append('')
        return '\r\n'.join(flattened)

    # Create the form with simple fields
    form = MultiPartForm()
    # заполняем поля
    form.add_field('_method', 'put')
    form.add_field('authenticity_token', token)
    # добавляем файлик (image/gif распознается автоматически)
    form.add_file('profile_image[uploaded_data]', 'image.gif',
                  open("1_bigger3.gif", "rb"))
    #заполняем следующие поля
    form.add_field('user[name]', 'Nameeees')
    form.add_field('user[url]', 'http://bla-bla.ru')
    form.add_field('user[location]', 'bla-bla')
    form.add_field('user[description]', 'test!')
    form.add_field('commit', 'Save')
    # формируем запросик
    request = urllib2.Request('http://twitter.com/settings/profile')
    # правим заголовочек )))
    request.add_header('User-agent', 'Mozilla/5.0 (Windows; U; Windows NT 5.1; ru; rv:1.9.0.13) Gecko/2009073022 Firefox/3.0.13')
    request.add_header('Referer', 'http://twitter.com/settings/profile')
    # переводим всё наше тело в строку
    body = str(form)
    # добавляем в хидер инфу о теле запроса
    request.add_header('Content-type', form.get_content_type())
    request.add_header('Content-length', len(body))
    # добавляем в дату тело наше ))
    request.add_data(body)

##    print
##    print 'OUTGOING DATA:'
##    print request.get_data()
##
##    print
##    print 'SERVER RESPONSE:'
##    print urllib2.urlopen(request).read()

    r = urllib2.urlopen(request).read()

print request.get_data()