Tools Required:

- Proxies
- Scrapebox
- Mass HTTP Header Checking Script (if you can't find one, outsource)


Step 1: Harvesting
These are your SAMPLE footprints [ add other web2's that give subdomains]
site: blogspot.com
site: typepad.com
site: wordpress.com
site: weebly.com

Use a huge keyword list, and good proxies.

Step 2: Sort by PR

Step 3: Extract only the high PR ones you want....