1) Clear your Xbox cache.

2) Get your speech level to 30 or over.

3) Find the "Big Town". Once you're there, go to the house just left of the bridge.

3) Inside that house there will be a girl named "Bittercup". Talk to her and find out that she had dated a man named Pappy.

4) After you do this, go find Pappy, and talk to him.

5) You should see a speech challenge choice while talking to him. Do the speech challende. (May not work first few times)

6) The speech challenge never goes away, allowing you to repeat you actions, earning you unlimited XP.