sharing wp_users table across different domains

Hi,

Is there any way to share a single users table across different domains? I already have 2 blogs running on different databases (call it A & B). I have installed wp-members plugin on both the blogs (Although right now only Blog A contains a list of members & there is no member for Blog B). Now I want to know is there any way (without heavily modifying the plugin for Blog B) so that the request to the user data (for login or any other purposes) for the Blog B is actually fulfilled by the data that is present in Blog A. I mean the request for wp_users table of Blog B is sent to the wp_users table of Blog A. There is no need to store data in users table of Blog B.

I was making changes to the plugin (by creating a new wpdb object). But I realized that it will require a lot of changes to work correctly. So I was looking for an alternative by which any request to wp_users table is fulfilled by the table which is on different domain. Is it possible?