Alexa’s Archive.org is one of the absolute best spots to find abandoned content. You can look up any old authoritative articles site and literally find thousands of articles that once performed in the top class yet no longer exist in the engines now.
1. Buy a domain name and setup Catch-All subdomains on it using Mod-Rewrite and the Apache config.
2. Write a simple script where you can pull content from a database and spit it out on it’s own subdomain. No general template required.
3. Setup a main page on the domain that points links to the newest subdomains along with their titles to help them get indexed.
4. Signup for a service that monitors expiring domains such as DeletedDomains.com (just a suggested one, there’s plenty much better ones out there).
5. On a cronjob everyday have it scan the newest list of domains that were deleted that day. Store the list in a temporary table in the database.
6. On a second cronjob continuously ran throughout the day have it lookup each expired domain using Archive.org. have it do a deep crawl and replace any links to their local equivalents (ie. www.expireddomain.com/page2.html becomes /page2.html). Do the same with the images used in the template.