One of my favorite blogs happens to be local to me. Eric Berger, the Houston Chronicle's "SciGuy" usually reports on the weather. But he also posts entertaining and serious stuff as well. [more inside]
UCSD physicist Tom Murphy inaugurates his blog Do the Math with two posts on the thermal limits of energy use on earth and the related absurdity of infinite economic growth.
Carl Zimmer's Science Tattoo Emporium - "Underneath their sober lab coats and flannel shirts, scientists hide images of their scientific passions. Here they are revealed to all." From the science journalist and writer responsible for The Loom and numerous other published works.
Fun Motion - a blog dedicated to physics-simulating games, currently with 49 reviews (and counting) of well known favorites like Stair Dismount and Truck Dismount, Towers of Goo, Toribash and many, many more. (A follow up to my previous YouTube post.) Kiss your precious, fleeting motes of productivity goodbye, cube-farmers!
Quantum Diaries - follow physicists from around the world as they experience the World Year of Physics 2005.
At Fermilab, one of about seventy high energy particle accelerators on the planet, scientists offer day-by-day, hour-by-hour reports of experimental progress and setbacks. Science in action looks tedious. This reads like a particle physics blog.