excerpts from multiple blogs on same server

Hi,

I have 3 wp installations on my website – say in the folders blog1, blog2, blog3. These cater to distinct topics.

I have a main page where I want to list excerpts from these 3 blogs.

So far I’ve managed to get posts from one of the blogs using –
require(‘./blog1/wp-blog-header.php’);
<– php code to display last 5 posts from blog1 –>

However, I am able to do this only for one blog. How do I pull the top posts from all the three to my main page in /?

ANY suggestion will be helpful. Thanks in advance.