How to share a table between two applications

Hi,

I have one user table in my rails application. I have created a database
(e.g. appDB). the appDB has a user table.
Then I have another application - Opinion forum - and a database
(forumDB) I want to share the user table in appDB in the forum
application.

This is to make sure that user logins for myrails app and the forum app
is common.

Is there a better way of doing this?

thanks

=Rajesh