Tony Duell wrote:
  In case you've not already heard, I have just been
told that Martin
 Gardner has passed away. 
Wow, I'm really sorry to hear that.
 He was, of course, responsible for many excellent books of mathematical
 puzzles. He had a defintie knack of being able to make something simple
 enough to understand but still keeping enough mathematics there to be
 worthwhile.
 The world is certainly a poorer place without him. 
Indeed.
 He certainly inspered me to love mathemaitcs. Had I not read his books
 some years ago, my life would have been very different. I don't think I
 am exagerating if I say that without his books I would not have passed
 A-level mathematics...
 True story : Many years ago I was given a couple of his books as a
 Newtonsday presnet. Once contained a chapter on base -2 arithmeatic. I
 spent the next day or so designing a base -2 full-adder circuit and
 soldering it up. Never found any practical use for it, but... 
You could always
solder up a computer around it. :-)
 -tony