I visited many co-workers blogs. It was fun to see their avatars and widgets and see what neat things they have been doing or creating with the tools they are discovering! I have used Google Reader since completing the 23 Things & 11.5 Things a couple of summers ago. It's very handy to have everything in one place and see it all in a glance. A real time saver! I follow Wired Science and The Onion on my other gmail account since I use Google Reader with that account more often. I have used articles seen here in the past to introduce some current scientific events to my students so that they can see science & biology in the real world.
PLNs are a cool way to collaborate with other educators. I love hearing or seeing things others do and then adapting them to my own students' needs. It always helps to have a fresh set of eyes on a topic! Since PLNs are for feedback, you just have to make sure that you monitor your commenting - keep it clean, constructive and professional since it's there for all to see.