Ask HN: Tips for flying with a guitar?

I'm going to be flying from New York to San Francisco tomorrow and would like to bring my guitar. Does anyone have any experience with this?

It's an acoustic guitar with a hard plastic case. I'm on a direct flight on a 757. What are my odds of being able to carry it on? I'm flying Delta, who has an explicit policy allowing guitars to be carried on, but they say that there are exceptions made (http://www.delta.com/traveling_checkin/baggage/special_baggage/musical_instruments/index.jsp)

Lastly, it's about a $300 guitar, but it was a Christmas gift so it is meaningful to me. Would it be safer to ship it insured with fedex or something?

I know this isn't tech related, but (a) I feel like there's probably a decent amount of musicians on here and (b) the best answer probably falls under the category of hacking a non-tech system :)