I have an Epson Stylus Photo Ex printer. It has a PARALLEL port. I'd
like to make it an ETHERNET NETWORK printer. Does a PARALLEL-ETHERNET
converter exists? How can I assign it an IP address? Via DHCP?

Just some general comments - not tied to your specific printer.

In laymans terms, a printer on a parallel port is relying on the host
computer to manage the ip address etc.  The printer is not designed to
be a stand alone printer.... it is designed to be attached to a
computer....

In order to use most printers that only have a parallel port as a
network printer, you can either use another computer or you can by
hardware that is designed spefically to manage the network connection.
 This is called a print server.

Some examples of print servers:
http://www.axis.com/products/print_servers/prod_list.htm
http://www.connectxpress.com/product_list.asp?cat_id=5505

-VBallGuy