How to install two wordpress BLOGS, but one user management

Hi

I want to setup two BLOGS (different installs or one install doesnot matter, but in different tables) but one user management, they should share the same users, so a user registered in BLOG A can have access in BLOG B, and vice verse how can i accomplish this?

I have searched the web, and found something about table perfix, and hacking the wp-config.php file but how do I deal with users, how do I make the one table wp-users available for the two blogs? That’s actually my question?

Pls don’t tell me to use WP MU