I just called Chase, and they said the travelers checks purchsed using their Currency To Go are considered a purchase transaction on your credit card, not a cash advance. I just thought I would let people know since we were recently discussing this.
My first order of AMEX Travelers Chegues from chase currency to go just showed up on my Citi AAdvantage card as "purchase", no added fees and $0 cash advance. It came next day Airborne Express. (No extra charge).