Halo Reach Commendations

Commendations are cool little recognitions that the game pops up to recognize stylistic things that you do.  They are designed to showcase what "type" a player is, since folks will tend to gravitate towards one type of commendation over another.  It's not explicitly clear what does what on same of the commendations, but here is some info I've found on the ones that pop for using specific weapons:

[Updated 10/19/10]

• Crack Shot: DMR, Needle Rifle, Sniper Rifle, Focus Rifle
• Sidearm: Magnum, Plasma Pistol
• Trigger Man: Assault Rifle, Spiker, Plasma Repeater, Plasma Rifle, Needler
• Heavy Weapon: Rocket Launcher, Spartan Laser, Fuel Rod Cannon, Plasma Launcher, Grenade Launcher, Concussion Rifle, Target Locator
• Close Quarters: Melee, Shotgun, Energy Sword, Gravity Hammer.
• EMP (not a commendation): Plasma Pistol, Grenade Launcher, Armor Lock
• Supercombine: Needler, Needle Rifle

I think that the Needler is an automatic weapon and counts towards Trigger Man but haven't confirmed it yet.  Jack of All Trades is mysterious because it counts "incredible feats", but this is the one I've progressed the furthest, so it must count lots of stuff.

There is an achievement to advance a commendation to silver, but I'm fairly confident that everyone will eventually get this just with playtime.