If I could find your older post, I’d link to it and close this one. Please don’t make multiple posts (and for goodness sake, don’t TELL us you’re breaking the rules! 😉 ).
Answer: Probably, but not easily. You’d have to share the posts table, because attachment data is stored in wp_posts. And I can’t think of how you’d do that without sharing all posts.
Which is why the post was filed under “Requests and Feedback” as, I was hoping to locate someone that knows enough about both WP and MySQL to develope a database that would handle uploads directly into a separate database/table that would be or could be commonly shared amongst several blogs…
[removed by mod]
My best suggestion would be to look at this post: http://channeleaton.com/2011/09/13/sharing-media-libraries-across-network-sites-in-wordpress/
I know you’re not using MultiSite, but the concept is you should be able to make a SQL call to the other database, duplicating the calls from media_upload_library();
