Great build, Jeff. Very snappy website, feels great to use.
Expansion on the categories may be super necessary, as there is no "politics" label, "Animals, pets, cute things" type category maybe too. 

A few phone/os/ type posts popped up that didn't really fit in with Science and tech > internet tech. Maybe more like a "hardware/software" option in there too.

I'm not sure how expansive you wish for this to be though.