I think you proposal is good. One option would be to give out some of the data that is behind HN, namely the information about who has upvoted which article. T

I think you proposal is good. One option would be to give out some of the data that is behind HN, namely the information about who has upvoted which article. This should make it possible to create mashup which would try to learn whose thoughts about interesting arcticles match mine. (No need to disclose the actual usernames, some anonymous identifier would be enough)