Many bloggers have years worth of content they've produced, but where are the personal tools that help them take better advantage of it? I've link parked the same link multiple times. There are long running, latent threads in my archives that could be packed up and re-presented to me. Why isn't there some little agent that looks at my blog posts, picks out the urls, and hits up del.icio.us, Google, Alexa, and Yahoo, for related material. It doesn't even have to post it directly to my blog, but just e-mail it to me to jog old memories or add different perspectives.
The blogosphere has a supremely short event horizon. Mining the entirety of an author's or self identified community's past publishing is an area where someone could make some real hay. And with even more sociable media mechanisms for people to splice themselves into, there's even more grist for the mill.