My personal blog is
It's not exclusively physics. Since it's a personal blog, it's about whatever interests me at the moment. When I do write about physics, the level is usually undergraduate (since that's my education level). I usually update in irregular bursts.
Some example posts:
Physics
Viete's Formula and Spinning Pizza
Uses simple physics to derive Viete's Formula
$$\frac{2}{\pi} = \frac{\sqrt{2}}{2}\cdot\frac{\sqrt{2+\sqrt{2}}}{2}\cdot\frac{\sqrt{2+\sqrt{2+\sqrt{2}}}}{2}\cdots$$
Fucking Geomagnetism, How Does That Work?
Response to Cosmic Variance's essay on Insane Clown Posse's "Miracles" video.
Bounce, part 2
Why won't a ball bounce higher than it's dropped?
Math
The Power Tower
What is $\sqrt{2}$ taken to the power of itself, over and over?
Answer, Lemming
A very cute puzzle from Ravi Vakil's "A Mathematical Mosaic".
Memoir
Why I Rode a Bicycle 200 Miles The Other Day
Pulse
Essay
'Simple' Isn't 'Easy'
Humor
Have You Ever Noticed A Panda Is Just a Fat, Slow Zebra?
Why I Don't Drink Soda
A Review of Reviews of Racism and a Very Sexy Reimagining
Comic
Sine Error: Spare Me
Sine Error: Tricked You!