Who you hang out with has so much to do with the quality of your life. I think about this all the time, so I was happy to see that the neurobiologists finally came up with some evidence that if you hang out with positive people, your brain actually starts thinking more positively (subscription soon).

I also think that friends who do cool things make your own life more exciting. My friend, Dennis, at Techdirt, sent the press releases to me about his company’s new product, and he was so excited that it made me excited, too. There is no neurobiology to support this — yet — but I am convinced that people who love their jobs give us more energy for our own.

When I played professional beach volleyball, everyone was always angling to be the worst on the court during practice, because that’s the fastest way to get better. This was no small feat when you’re at the top of a sport. But the day I had a match against Olympic gold medallists, I learned more about myself and my game than from 20 matches with people at my level.

A blogroll, to me, is a metaphor for all of these issues. If you are the sum of who you play with, then I want to choose my list of blog playmates carefully. When it comes to blogrolls, some people have very thorough lists of everyone in their field.

My list — which I’ve titled, What I’m Reading — is the blogs that make me excited and get my brain moving in new directions. The list changes all the time. A lot of the blogs aren’t career blogs. After all, I dream up ideas about careers all day. But you could say that your career is closely related to the people you play with, and in that sense, these are all people who have helped my career most recently.

(Hat tip: Willy in Wisconsin)