If you’re flying somewhere and the flight is actually long enough that you get a meal, call the airline in advance. The number of dietary preferences they can accommodate is pretty amazing, including vegan.
Another nice perk of getting a special meal is that you get yours before all the other passengers. No craning your neck to see when the flight attendants will get to you 🙂
As an example of what you can expect from vegan airline food, I recently flew on US Airways. Dinner/lunch consisted of a green salad or mixed fruit, roll with vegan butter, and a main dish of rice/peas/roasted veggies. The snack was a roll with a veggie spread and a nectarine. Breakfast was a bagel with jam and vegan butter.