I was in Seattle a month ago for AMD Fusion conference. Here my dialog with the Immigration Officer:

    I.O. - "What's the purpose of you visit?"
    me   - "I come to the AMD conference"
    I.O. - "For how long do you visiting US"?
    me   - "8 days"
    I.O. - "How many days is the conference?"
    me   - "3 days"
    I.O. - "So why do you come for 8 days??"

;)

Re: "Dr. Nefario" - I can't believe he has no credit card.