usrp_drm_rcv.py is the graphical dream gnuradio example.
You need drm_rcv.py in the same directory (This is the guts hierarchical block for dream used by usrp_drm_rcv.py)

The example will automatically start dream for you and open a pipe with a stream of samples for dream in the right format (on linux)

So for the dream python examples you need to have a version of dream installed.
You can find dream at:
http://drm.sourceforge.net/

You can also find patched sources in http://www.olifantasia.com/projects/gnuradio/mdvh/examples/dream/required/

drm-patch-mdvh.diff is a patch I developed to get dream to work on my machine (debian sarge).
There is a little bug in the original drm-1.6.25 source.
It hangs if cat /dev/sndstat gives out lines with more then 20 chars.
This patch solves this.

I also put up a source tarball in required which includes this patch.

I also found some binaries on the net for debian which also seem to work
You can find these at:
http://duch.cz/drm/dream/debian/

Greetings,

Martin Dudok van Heel
(for my emailadres look at http://www.olifantasia.com/gnuradio/ under Contact.
You can also try at nldudok1_olifantasia_com but I don't check this email regularly because it is bombarded with spam)