2. don't talk about the blockchain. its even more confusing.
3. say that bitcoin is "digital gold". that'll definitely make them sit up.
4. say that only a fixed number will be issued and then NO MORE.
5. say that since its digital it can be instantaneously transported across borders w/o detection. they'll immediately realize the implications of this.
6. don't say anything about "cryptocurrency" or "cryptography". this makes it sound like bitcoin is trying to hide something along the likes of Silk Road and other illegal activities.
7. say that bitcoins are secured by "advanced mathematical algorithms" that prevent counterfeiting. sounds impressive.
8. try to avoid saying anything about Satoshi since an unknown character brings to mind a shady type character or hidden agenda.
9. do explain that the decentralized or "spread out" nature of bitcoin computers makes it indestructable to gov't or Fed intervention. they'll like that.
10. when they ask what its denominated in say that bitcoin is a currency UNTO ITSELF and "floats" in value against other fiat currencies like the USD but bitcoin is in fact NOT a fiat currency. you might mention that you think that bitcoin will become the gold std against which all other currencies will be measured.