Having a high Charisma will improve people’s disposition of you, and give bonuses to both the Barter and Speech skills.

“You’ll find there are some smooth-talkin’ cowboys out there that got themselves a voice that sounds like an angel’s harmonica.”

Charisma isn’t any better in New Vegas than it was in Fallout 3, with the exception of the bonuses it gives to your companions’ nerve, which significantly increases their Damage Threshold and Damage. Still, this is a character creation guide aimed at making the strongest character for this game as possible… not for making the strongest companions. At the end of the day it’s probably better to have a strong main character than a strong side-kick. Keep the benefits in mind, sure, but realize that a high Charisma is going to cost you in other areas. Use it as a dump stat and let Speech and Barter get you through the conversations in the game.

Start out with one point in Charisma. There’s really no great reason to start out with more. If you want to be a silver-tongued devil, get a high Intelligence and just use Speech instead.