But they have JetBlue. The airline is now offering student discounts of 11% off all of its flights, anywhere, at any time. To qualify, you've got to have a valid ISIC, ITIC, or IYTC card (if you're a real student, you'll know what those are, or your administration will).
You have to love it. One thing you notice when you travel abroad is that nearly every tourist attraction outside of America offers some kind of deal to students, while here in our country, we generally stick it to them to pay the full price everywhere at a time when they're supposed to be soaking up experiences. If airline seats are going to go empty in these times, it's good to see them discounted. It may not be outright charity, but it's at least a little more charitable.
Students can sometimes get airfare discounts on foreign airlines and occasionally from the major U.S. carriers (especially if they buy packages, as with American Airlines), but the non-legacy carriers, already being perceived as cheap, have not been steady sources for student deals.
Southwest Airlines sells Youth Fares by phone only, and they go to kids aged 12 to 21, but they may not always be cheaper than an adult fare that's on sale -- they're just unrestricted. AirTran, for its part, has offered its own version of a student discount, AirTran U, for years now. It grants $69 to $99 each way for flights -- but you have to fly standby.