Well, I'm really behind on responding to all of your posts due to too much work (a good thing in this economy). I'm glad to see that I'm not alone in trying to figure out how best to use social networks, and that other creative folk think they're important.
Taylor is very focused and regular about her use of social networks. I'm focused but, as you can see by how long it took me to respond to your posts, not very regular. I try to check in with biznik at least a few times a week and update my LinkedIn connections whenever I meet new people. Twitter is easier for me to keep up with because I can schedule a bunch of tweets for a week or two at one time.
Kimberly mentioned being disappointed about not getting any work through social networking yet. I think that making those types of connections will come over time, as more people join social networks, including more of our potential clients.
Also, I've found that networking, social and otherwise, works best when you look at it as planting seeds, that is, something that will grow in the future, rather than an immediate way to get business. Provide useful information to others and serve as a resource in other ways (e.g., by connecting people), and the business will come. For example, in the past few weeks I've gotten 4 inquiries about my services. One came through social networking, one was from someone I met about 10 years ago and have been in touch with occasionally since, and one came from someone in a professional association I belong to. I have no idea how the fourth person found me, which means that someone in my network must have told him about me. This happens at least 3-4 times a year.
So, keep on social networking.