If you are a member of a number of social networks and don't want to manually update all of them, you start looking for a workflow that will enable cross-postings or relay of information, in order to reach these various services without having to spend too much time with them. But this can cause issues of duplication, such as when two different aggregators place the same item in Facebook. I never really sat down to carefully work out all the connections between the various networks that I use and, as I discovered, even four or five different services create endless complexity. What's more, it is unlikely that there are two people who use exactly the same set of services, so googling to find a solution isn't very successful in this case. Eventually, after making four or five pages of pencil notes, and doing lots of erasing and re-writing, I figured out a method that will probably work better.
I understood that the basic services I need to consider are blog, status blog, links and photos. Other kinds of information are less important for me, since I deal with them less. My basic publishing sites for these kinds of information are currently my blog/lifestreaming site, Facebook, FriendFeed, Twitter, Twine and Picasaweb. These services support varying degrees of interoperability and sharing. For instance, it's easy to get information into Facebook, but harder to get it out. Twine is a network based on interest groups around hyperlinks, but when Twine links are aggregated through other services, they link back to Twine, rather than to the original articles. Friendfeed aggregates everything, and can pass on information selectively to Twitter.
I discovered that I have to deal with each publishing category differently, but when I had hit upon the right method, this could save me a lot of time. For instance, for links I can take a news item aggregated by my rss reader, then email the link simultaneously to two different services, which will then relay the link through my networks. For my photos on picasa, I can publish both to picasaweb and to Facebook (using picasa's facebook plugin).
Like lots of things in IT, a little time spent setting up a workflow program saves lots of work and annoyance down the road. In this case it's hard to attain a perfect system, but possible to devise one that works reasonably well.