DD begged me to teach her to read when she was 3.5. So I did (using phonics.) She caught on very quickly and has been a voracious reader ever since.

DS seems to have learned to read from a LeapFrog video called "Letter Factory" when he was about 2.5. I used to let him watch it every morning when I was in the shower. One day we were playing with some magnetic letters at his preschool and I discovered he could read simple words.