Depending on 1) How much time you have, 2) How many available segments you have of your 16, and 3) what time of the year you are traveling (the following only works June-Sept) you may want to consider the following:

SFO-DFW-ANC Visit Alaska
Take a cruise from Alaska to Vancouver (surface segment counts as 1 segment of your 16)
Do your visit of Vancouver and then continue your itinerary to JFK and onward.

Note: AA DFW-ANC service only runs June-Sept and schedules for 2010 should be released between now and mid-October which means if you purchased your xONEx now, your ticket would have to be open dated. Not that that is a big deal, just an FYI.

I am doing something very similar for my AONE3. 9 days in Alaska, a Celebrity 7 night Cruise form Seward to Vancouver, and few days in Vancouver and then CX back to JFK.