http://www.ExpertVillage.com is a video site that is chalked full of content that you can have transcribed and/or written about – then posted on your own site. Written content is currently the only content that the search engines can read, so transcribing this content will give you fresh-new content.

Research Beyond Google: 56 Authoritative, Invisible, and Comprehensive Resources

http://www.deepdyve.com

Yahoo Answers – There is loads of quality content here that you can post to your blogs/properties. It’s public info that more than likely isn’t already on a lot of other sites.

http://www.gutenberg.org/catalog – This is public domain content – and sometimes you can finds good stuff here – enough for full promotion.

http://www.wikihow.com  – more content

www.archive.org – Can be used to find older content, podcasts and videos that can be transcribed and used.

Also, you can locate content that is written in other languages – and have it translated to using Google’s Translator tool.

Google Alerts – Google Alerts are email updates of the latest relevant Google results (web, news, etc.) based on your choice of query or topic. You can have it sent to you at any sequence you wish.