To Get Halo 3's Reconz Armor:
You Have To Get All 7(yes 7) Vidmaster Achievements From Both Halo3:ODST, and Halo3.
Then You Go To Bungie.net, If You Have A Windows Live Account, Sign In To It And Go To Your Service Record
Spot, And On The Page Somewhere It Should Say "Get Recon"
And That's How You Get Reconz Armor For Your Halo 3 Multiplayer Character.
(P.S.=I Found This Out On The Bungie Site)