Algorithms and complexity theory blogsLance Fortnow and Bill Gasarch's blog, Luca Trevisan's blog, Andrew McGregors's blog.
Life of a grad studentPhD (Piled Higher and Deeper) comic strip, To be or not to be a grad student-- by Karthik Shekhar, How to write your first research paper? -- by Steven Krantz
Geeky/nerdy stuffA mathematical love song, BBC documentary on Fermat's last theorem, Xkcd A webcomic of romance, sarcasm, math, and language,
Animal welfareThe lesser known laws regarding stray animals, stray feeding guidelines