this might be interesting for some people who don´t have all those wordpress sites on the same server or database:

MultiX is a lightweight WP-Plugin that allows the seamless administration of multiple Wordpress websites that can reside on different servers and databases. This plugin is a way for those of us that need to administer multiple Wordpress websites but don’t have the luxury of having all those sites on the same server or database.

http://www.thisrand.com/scripts/multix

btw, are there any other good solution to manage multiple WP instalations on different servers from one place?

Originally Posted by rayray

btw, are there any other good solution to manage multiple WP instalations on different servers from one place?

Yes, but it is a pay solution (www.wordpressmassinstaller.com) it will allow you to do this

WordPress Mass Installer
-Install 1000 WordPress Blogs per hours
-Manage multiple blogs from one place
-Extremely Fast WordPress Installer
-Create multiple blogs on 1 website or several websites
-100 Blogs on multiple web servers in 60 seconds
-Manage each Blog's Settings before installation
-Administer your WordPress themes and plugins
-Activate and desactivate WordPress themes and plugins
-Easily set default Blog and Ping settings
-Create and manage WordPress Categories for each blog
-Easy Blog management system
-Most used Wordpress options already set
-WordPress Mass Installer
-Create numerous blogs each unique
-User friendly interface
-Manage blog on any server anywhere
-Add all your existing blog
-Manage your ping URL lists
-Add and manage blog from all major blog hosting provider like wordpress.com, etc ..
-Easy build and simple web publishing solution with no HTML knowledge or web design skills required.

Articles Posting and Management
-Add 1 to 10,000 articles to your account using your control panel
-Manage (write, edit, delete) 1 to 10,000 articles
-Build in WYSIWYG editor
-Turn 1 article to 1000's using build-in synonimizer
-Build-in text synonimizer,rewriter and processing of unique articles
-Ability to set rewrite percentage of article(s) like 10, 20, 35 ... %
-Post one article to 1 or 1000 wordpress Blogs
-Post 100's articles to 1 or 1000 wordpress Blogs (each article will be unique)
-Schedule articles posting to wordpress blogs
-Ramdom articles posting to blogs

Links Strategie and Management
-Blogroll links management
-Post 1 link to one or all your blogs
-Automatic SEO blogs interlinking

I don't quiet get it. Does it basically just sync the username and password so you could switch from one wordpress to another without login and logout? or any advance features?

Interesting

Actually, it moves you back and forth between the sites without having to re-log in or type in the URL. It uses a two way trusted key method of authentication. I am open to suggestions for more advanced features though.