Fallout: New Vegas Glitches

Free XP
To start off, go to Cottonwood Cove. Once there, go to Aurileous of Phoenix, his office is in the middle of cottonwood cove. Now, wait until he's in his office sitting at his desk, and with 50 speech, activate the skill-check, it will give you 38xp. Now, once you clear the screen, you will see that you can do the skill-check again, and get the same amount of xp. Depending on how fast you click, you can get 100-500 xp every 3 seconds. (Note that this is similar to the Fallout 3 glitch, but this gives you much more xp)

P.S. Try not to do this on your first play-through, it will ruin your gaming experience.