I don't have much use for twitter, ie, I don't feel that I add anything useful and I have yet to take anything useful away. However, I won't delete myself completely for fear that as soon as I do, its true purpose will become evident, and then I'll just have to go back and re-lete myself. Anyone else have the same problem? No? Oh well.
I (kind of) do like facebook. Not as a daily, constant thing, but rather as a once-in-a-while, when-I'm-bored-and-can't-write-a-post kind of way. It's fun catching up with people I haven't seen in years and connecting with new friends, but it also has its limits. Want to stalk someone? Facebook can help you out. Want to show others how cool you are? Facebook can help you with that, too. Interested in having a real life? You might want to re-think your options.
The concept behind LinkdIn evades me still.