I appreciate the comment. I too rarely cross post as I value the time of those who follow me just as I hope they value my time. The reality, though, is that most people pollute their streams with all sorts of cross posting between networks. My efforts at treating their streams with some respect more than likely go unnoticed.

We regards to filtering of stream content, that is a much needed feature with many social networks. I wrote about that in my detailed article, A Flock of Twitters: Decentralized Semantic Microblogging. You may need to read the first half of the article to make sense of some of the issues I discuss.

Like I mentioned in my post you linked to above, if the services you using don’t provide your follows to filter properly, if you don’t want to lose followers, you need to take matters into your own hands and manage how your data flows from place to place. Personally, I post directly to each service as appropriate. If there is something that is appropriate for all places I participate in, I currently use Ping.fm to pass that message on to them all.