One of my all time heroes died, yet I could not find words adequate enough to pay tribute to him. Phil Plait wrote eloquently about his life and influence, as have James Randi and Richard Dawkins. Scientific American, which he wrote for for a quarter of a century also paid tribute with three of his puzzles.
Anthony Barcellos posted a multi-party interview with Martin Gardner. Ben Goldacre also paid tribute, as well as noticing what has changed since Martin started writing about pseudoscience.
P Z Myers paid tribute, as did PodBlack Cat, the Quantum Pontiff, Gathering 4 Gardner, Selva at the Scientific Indian and Evolutionblog.
Reading these, I realise that Martin Gardner had an extraordinary influence through his writings - he taught people about mathematics, skepticism and critical thinking. He showed that joy could be had in exploring mathematics and that there was beauty in it. He was no Gradgrind, but a quiet, shy, gentleman with a love of conjouring.
The influence I can trace in my own life: Science: Good, Bad and Bogus was one of the first works that interested me in skepticism (the other being The Bermuda Triangle Mystery - Solved by Larry Kushe). I looked for more of Martins' books and gathered a collection of his books - mainly columns from Scientific American - over the years. (Somehow, I didn't start reading Scientific American until after his columns ended.)
His explanation of a tic-tac-toe machine that learned was a revelation. (It was an analogue machine, made of matchboxes, other pieces of cardboard and coloured beads.) This sparked an interest in artificial intelligence that, combined with an interest in puzzles, probably interested me in computers to the extent that I make a living programming them.
Martin Gardner taught people all over the world, sparking curiosity and encouraging them to ask questions.
Vale, Martin. You were one of our greatest teachers.