I'm sure many people here are familiar with the man - but if not...
Alan Turing is one of many people whose work has, eventually, enabled you to read the words on this screen. He created a theoretical construct that proved various limits about the nature of solvable algorithms, and this construct, in its most basic form, became the Turing machine - a simplistic, if impractical, expression of the computer and the logical means by which it could be programmed and communicated with. A slightly more complicated - and limited, due to the lack of infinite resources to use - version of the Turing machine functions as a model for most modern computer languages.
Turing was also instrumental in cracking German codes during World War II. Without his work, Britain would not have fared so well leading up to America's entry in the war.
After the War, he provided a great deal of insight into the beginnings of artificial intelligence research.
Given little thanks for his efforts, Turing was tried and convicted in 1952 for 'gross indecency' - being a homosexual, and forced into hormone treatment. This led him to a major depression and, in 1954, he committed suicide by eating a poisoned apple.
I've been hearing others comment that "If one person deserves an apology, others do." regarding the petition I linked above.
That misses the entire point. No matter who - or where - you are, Alan Turing changed your world for the better.
He deserves your memory.