I'm in a similar situation with my 6 year old son, and the advice and links in this thread proved helpful.
As a summarized recount, below are some of the things I noticed about my gifted son throughout the years (may be helpful to others):
At age 1, he memorized the entire alphabet and could count to 10. He began talking in complete sentences by 15 months. He learned all the colors and shapes, including what a trapezoid was, by 18 months. He started adding things a month after he turned 2. At age 2 1/2, he said he wants to go to college. He could tell the time at 32 months. At 34 months, he started reading. A few weeks after starting to read, I taught him the American Sign Language, which he picked up quickly. When Lyle turned 3, he wondered why day turns into night and vice-versa. He then learned about the Earth's rotation and would proudly relay this fact to anyone who'd listen. At age 4, he enjoys putting puzzles together and is now able to complete a 100-piece puzzle of the United States map on his own (recommended age on puzzle box says "For ages 7 and up"). As a 4 year old, he was able to read Grades 2 and 3 level books.
Lyle, at 5, started Kindergarten last August 2005. His teacher gave him a Reading Comprehension test, and he's currently above Grade 6 level in Reading. He's had Literacy Specialists and GATE Specialists come see him.
At 6, he's a talker. I mean a real talker, who can talk to anyone about anything and everything. He preiodically reads the almanac and encyclopedia. He has a great memory retention. He's also a very normal 6-year-old who loves the Power Rangers, basketball, video games, computers, and being around other kids.
