Two sites – under one roof

I’ve got an interesting problem. I’m creating a new business site agilepainrelief.com – so far so good. The difficult part – my blog notesfromatooluser.com has been around for a few years and has some good pagerank which I don’t wish to lose. Any ideas on how to integrate the blog (it will be migrated to wordpress) with the main site and still maintain the pagerank (presumably maintaining the notesfromatooluser domain)? I just a pointer to a good article on subject.

Cheers
Mark