After months of no play I've come back to Halo 3.  First step was to browse the mlgpro.com site (Major League Gaming), and find that many people are using the Bumper Jumper control scheme.  I decided to not only change my standard control scheme, but to go all out and become accustomed to playing with my trigger fingers on the bumpers and middle fingers on the triggers.  This way I can fire, grenade, melee, jump, move, and look all concurrently without having to move any fingers.  Last time I made a major change to my controls I went from Inverted to Default, and that took a couple weeks before it was second nature.  I suspect a similar learning curve, but even better benefits.  Time will tell...