For his research but more importantly his writings on the ethics of cryptography & the place of technology in society check out Phillip Rogaway's site, especially his sociopolitical essays.
Angels is one of my favourite very simple games. Conway's game of life is visited by an angel - can you spot her? Defocus your eyes and find the aberration in order.
I love Discworld, and Pratchett is even better with the Annotated Pratchett File as a companion. Check it out for extra comments/notes/explanations.
Ever wanted to know what you learn in Clown School? I did. This article collects hilarious stories from performers of clown on their journeys and what they learnt.
Find here a fascinating article from 1989 on meta-materials in F1 cars. It gives great insight into the design/engineering/crash-testing of cars at the time.
While I mostly listen to metal/emo/alternative I hold a place in my heart for instrumental music, especially in uncommon ways/combinations. Banjo + synths was not a combo I expected to work, but it's incredible. Another instrumental song I'm currently obsessed with is Angelica by Lamb (as recommended by my brother)
The National Parks Service (of the US) has crochet patterns written by rangers. I have made the Walleye and the Halibut (one of my favourite fish).
Currently working on finding a better source, but for now just check out the Wikipedia page for WWII Code Talkers. The Code Book by Simon Singh is a great source for more information if you can get your hands on it!
I'm super not a fan of the concept of going in caves myself, but luckily Carla Kirby is because she's created this wonderful site filled with her own original images and thoughts of all things caves. Cool stuff!