Lets see... it was my little brother who brought home his first Xbox and CE one week after release. Watched him play a few missions and left the house, came back 30 minutes later with my own controller... so... it was Octoboer or november 2001 I started. Attended a few LAN's for CE, participated after I saw three, then the great information collapse from bungie.net lost the records (I still shake my fist in anger. lol). Halo 2... I was one of the people who wanted my pistol back and signed up on halo2sucks.com, that site is down now...
So yeah, late 2001, one week after release.