Unlimited Movement Points:
First get into the combat mode. Then take ammo for a gun and put it in your hands (only ammo should be in your hand!). Now come close to an enemy guy and click on target to shoot him. He should say something like "Did your mama teach you that move?!". You should now have unlimited movement points.
Talk to the guy in Doc Morbid's basement in Junktown. Get him to tell you about the doc's deal with Iguana Bob in the Hub. Talk to Bob and blackmail him into paying you every five days. Talk to him at night and he should give you some money. Keep talking to him that night and he should give you caps each time.
To get lots of experience points, go to the Boneyard and kill the Deathclaws for 1000 points each. After they're dead, rest for one day and kill 'em again. Keep doing this until you get bored. --- or --- Kill the MOTHER DEATHCLAW in the basement of the building where the deathclaws were, then talk to Gabriel of the Gunrunners and tell him you killed her. Walk out of that screen, come back in and tell him again. Keep doing this.
Rescue the initiate of the Brotherhood of Steel in Old Town in the Hub. Go to The Brotherhood and become a member. Talk to the guy in the training room ( on the first floor ) who's wearing power armor and ask him if you could have some. If he agrees, talk to the guy behind the table outside the door to the training room and he'll give you some. Next, go the 3rd floor and talk to the knight about the power armor he's trying to repair. Ask if you can have it, then go up to the first floor again. Rest until midnight and then wait for Rombus to go into his back room. Run in and take the systolic motivator from his locker and RUN out. Go back to the knight and get the power armor. That's two! You can sell one for beaucoup money!
This is an Easter egg, doesn't help much in the game, but fun. Hold down the Shift key when you click on the credits button from the main menu to see quotes from the makers of the game. Some of them aren't suitable for kids....