Import a regular WordPress blog into a MU installation

I am looking for a safe way to import independent blogs into a WordPress MU installation.

The basic idea is to merge multiple blogs running on subdomains into a single wordpress installation with MU feature.

I can use the WordPress export/import feature but it would not work in my case with some of the blogs having a lot of content. I have played with this option. Not worth it. Export would time out even on localhost.

I also need the postid to remain same so that links do not break.

I have spent a lot of time looking at the options I have. Import using PHPMYADMIN seems to be the only way out. But I am not sure what would be a safe way to import using this route!

Any ideas!

I don’t know of you like the sound of domain mapping but check out http://codex.wordpress.org/Migrating_Multiple_Blogs_into_WordPress_3.0_Multisite and check out number 6 if they are on the same server. If not import seperate install into them so that number 6 works.