Sharing 1 physcial Printer across 2 networks

the fastest way without joining the two networks is the purchase a print server device.
the make both USB and serial ones that will provide the functionality of a second NIC card.
you can get them at most electronic stores.
here is a link
http://www.google.com/products?rlz=1T4GPTB_enUS291US292&q=print+server+usb&um=1&ie=UTF-8&ei=y7CzS5KzC8H7lwfz_uC6BA&sa=X&oi=product_result_group&ct=title&resnum=3&ved=0CDsQrQQwAg

If the Ricoh has a routable IP address you can do it.  You've got to be able to see past the firewall/router on the network you are trying to access the printer on.  You may also do port forwarding to an internal IP address for the printer.  Or if the Ricoh has a web server built in and can be seen from outside the DMZ you may be able to access it that way.  In short, two separate networks aren't usually designed to let just any other network or computer have access without being configured properly since security issues are a factor.

Thank you for the recommendations.  I just took over a new client who was sharing an infrastructure with another business.  Not good.  I'm in the process of separating my client from the shared infrastructure.  My only snag was that both businesses still want to share one common multifunction ricoh printer.  Hence, my issue architecting a solution that will work for both but also be secure and separate.

I'm sure Ricoh has something that does broadcasting, or you can assign an external IP (if you have one) or port to where it does to an internal IP for the Ricoh.  There are a few ways to do it, depending on the network.  Good luck!

You could also connect via usb to a pc on one network and share it from that pc. The network port could then be used for the other network. Ok, you would have to have the pc on all the time, but it would be secure.

Thanks again for the recommendations.  I will post a follow up message when I get it implemented.