Quick and dirty :
checkout, compile and copy the ecouch directory somewhere erlang will find it. Mine is
/usr/local/lib/erlang/libdownload this, compile, copy the beam file in the ejabberd
ebindirectory.in ejabberd.cfg :
{modules, [
.
.
.
.
{mod_couch, [{server,{"127.0.0.1", "5984"}}]},
.
.
.
]}
restart ejabberd
You now have access to your CouchDB server within ejabberd.