On lookout for good corporate blogs

I just Twittered in search of good corporate bloggers. Looking for ones who have a voice, engage, do interesting things. Aaron Strout pointed me to a Dell blog. I read a couple posts that seemed like standard PR, but then came across one by Lionel Menchaca (about Facebook and Twitter at Dell). Different beast altogether. Other examples I should look at?

Before it's here, it's on the Bloomberg Terminal.