I write an intermittent newsletter, Metafoundry (with thanks to Warren Ellis for the name). I mostly talk about technology and culture and other obsessions of mine.
WIRED included it as one of their "21 Must-Follow Feeds for Business" and it's on this WNYC list of 'newsletters you'll actually be glad to see in your inbox'. But my favorite description of it comes from Clive Thompson, in his WIRED piece on newsletters:
The pleasure in reading a newsletter comes from the view into a unitary mind at workâlike my single favorite newsletter, Metafoundry, by my friend Debbie Chachra, a materials scientist. Reading it is like being plugged Oculus-style into her brain while she meditates on science and culture.