Concepts from the echo chamber.
The first idea is from a post linked from HorsePigCow and relates to using images to test for human versus bot posting. Basically, you can use this concept to combat comment spam or similar. If you run a lot of web sites like we do, you feel my pain and can see the potential!
The second is this post on "piggy back marketing" discussing basically commenting on every blog post a competitor has.
Via Rubel: PR Newswire has launched a podcasting service. I feel so "mains tream"