Last year booked a SDJ-GUM flight for 25k miles using up some about-to-expire Delta miles. The delta guy didn't believe it was possible but once he actually inputed it there were no problems. You can use CO's website to find availability and then call NW. The really nice thing is that airport taxes seem to be really cheap - I paid $20 last year - $10 for airport taxes and $10 for Delta's handling fee. CO Micronesia's service was great. They were kind to everyone - even the Japanese. (I've seen some other airlines (not NW) treat non-English speaking passengers horribly. Even though I'm not Japanese, I refuse to give my service back to those airlines!)