Giving up your US citizenship

Seems to be alot of talk these days about US Citizens giving up there passports to find greener pastures elsewhere in the world. A friend passed me this audio clip which provides some excellent information on terminating US citizenship:

http://c2.libsyn.com/media/21366/Mark-Nestmann-Renunciation-20100825.mp3

• Difference between renouncing and reliquishing
• Cost of giving up your US passport (overview)
• Can you still travel to US if you relinquish USA citizenship?
• Can you get citizenship/residency back if you give up US citizenship.