Fallout: New Vegas companions

Companion wheel
The companion wheel is a new feature that is added to Fallout: New Vegas. The wheel provides easier control over non-player companion characters in the game.

There are 8 sections on the wheel, each with a specified function.

The available orders are:
 * Toggle melee/ranged fighting
 * Open inventory - This displays the companion's current inventory, inventory weight, and weight limit.
 * Toggle stay close/keep distance.
 * Back up.
 * Toggle aggressive/passive AI.
 * Use stimpak.
 * Toggle wait here/follow me.
 * Return to normal dialogue.

Permanent companions
You can have up to two companions, one humanoid and one non-humanoid. All companions default weapons have unlimited ammo. All companions are listed as essential on all difficulty settings except hardcore mode, where they can be killed.

Humanoid companions

 * Arcade Gannon, a member of the Followers of the Apocalypse with a mysterious past. He can be found in Old Mormon Fort.
 * Craig Boone, a very-talented Ex-NCR sniper with a grudge against Caesar's Legion. He can be found in Novac.
 * Lily Bowen, a friendly nightkin and former member of the Master's army. She can be found in Jacobstown.
 * Raul Tejada, a ghoul mechanic and former gunslinger held hostage by Tabitha, the mad leader of the State of Utobitha. He can be found in Black Mountain.
 * Rose of Sharon Cassidy, a caravan merchant and the daughter of John Cassidy. Also known as Cass. She can be found in Mojave Outpost.
 * Veronica Santangelo, a disillusioned Brotherhood Scribe. She can be found in 188 Trading Post.

Non-Humanoid companions

 * ED-E a prototype eyebot designed for combat and reconnaissance operations. It can be found in Primm.
 * Rex, a cyberdog belonging to the King. It can be found in The King's School of Impersonation.

If you're hunting the "The Whole Gangs Here" achievement there appears to be a glitch that you can get the achievement without actually recruiting all companions. While attempting to get this I was going around to all possible companions and recruiting them but as soon as I did I dismissed them so I could continue my companionship with my buddy Raul. It appears the achievement is triggered by how many times you successfully recruit a companion regardless if you already have or not, so you can exploit this by continuously dismissing your companions then recruiting another. Though you can do this I advise against using this as a excuse not to visit all companions, all have some kind of quest attached to them and add more length to the fabulous Fallout experience so still go check em out and enjoy your stay!

Temporary companions

 * Neil, a disgruntled super mutant.
 * Sunny Smiles
 * Trudi
 * Deputy Beagle
 * Private Halford
 * Victor

Returning Lost Companions (PC)
Push the Tilde key and then type in.

The Ref id's for companions are listed on their respective pages.

You can use (instead of both commands stated above) too - if you want to know where you lost your companion. Be sure to make a new save before using any Console Commands.

See Console Commands for more information on how to use the console.