e should all have to reinvent ourselves at age 16.

Lil' Bow Wow became famous after being discovered at 6 by another canine-theme rapper, Snoop Dogg. And last year 50 Cent boasted in a rap, "We ride around with guns the size of Lil' Bow Wow." But the pint-size rapper is now quart-size, and has dropped the Lil'. The grizzled veteran of a teenager has decided it's time to give something back. So he showed up in Midtown on Wednesday to promote Computers for Youth, a group that provides computers for New York City schoolchildren. At a press conference, Bow Wow rapped a few lines, including, "Fourteen, I done started up a whole epidemic." The age reference was anachronistic since it was taken from his second album, "Doggy Bag," Bow Wow told us afterward. His entourage towered over him and a cuff-link-size diamond sparkled in his left ear. "I use the computer for everything," he said. We asked if the rap slang drove the spelling and grammar checks crazy. "Well, that's the one thing I don't do on it," he said. "For that, I use a pen and notebook." But once a rhyme is written, he said, he never forgets it. "Never," he said. "And if I do, I have Plan B" Which is? "Stop the music and start over." A group of schoolchildren descended on him, including Ewan Douglas, 13, of Brooklyn, who displayed his computer literacy by holding up his autograph and yelling: "Yo, I'm gonna sell this on eBay for $50."