This doesn't exactly answer your question, but if you are looking for an interesting free, open-source project that is written in Erlang, you should definitely check out CouchDB. From the website:
Apache CouchDB is a distributed,
fault-tolerant and schema-free
document-oriented database accessible
via a RESTful HTTP/JSON API. Among
other features, it provides robust,
incremental replication with
bi-directional conflict detection and
resolution, and is queryable and
indexable using a table-oriented view
engine with JavaScript acting as the
default view definition language.
CouchDB is written in Erlang, but can
be easily accessed from any
environment that provides means to
make HTTP requests. There are a
multitude of third-party client
libraries that make this even easier
for a variety of programming languages
and environments.
The CouchDB website has more details. Happy coding!