Why am I using these services nearly every hour of my waking life? Because they are being talked about and I want to learn what is making people so passionate...trying to figure out what they are good for and whether the hype is justified. In my opinion:
Ping.fm is a simple service that cuts out the middle man when it comes to posting to your social services such as Facebook, Twitter, Jaiku, Tumblr and Pownce with more being added soon.
A great speech by Jyri Engestrom, co-founder of Jaiku and sociologist. In the first part of his presentation he explains his concept on socio-material objects. 49:40, very down-to-earth.