Multiple blogs, multiple loops

I have a number of WordPress installations and want to show the latest two posts from each blog on the front page of the site.

I have tried using multiple loops, but once I’ve connected to one blog (with get_posts, query_posts or even starting a new WP_Query) it won’t connect to another blog. I.e., it just shows the same two posts from the first two blogs.

I know you can do this with feeds, but I would prefer to do it using wordpress methods since that would be more efficient.