Most of my overseas flights have been on Delta or a partner. It would be nice to have some of those flights be free. If you create a Skymiles account, your next trip could be, if you accumulate enough miles. Go sign up here.
Better yet, sign up, as I did, for the SkyMile AmEx and get enough miles for a free flight now. This is the card I had (but stupidly cancelled) when I earned my first 50,000 miles. I am now at 65,000.