We describe recent results on source coding problems where a helper
provides rate-limited side information to the involved parties. We
first describe previous results on a regular rate distortion problem
where a helper provides common rate limited side information to the
encoder and decoder. Then partial results are derived for the case
where the helper can send different information streams, of
different rates, to the encoder and decoder. Finally, the Wyner-Ziv
problem with a helper is studied, again for the common and
independent helper messages models.