There is no good car seat alternative, for the car, for babies under 3 years old. There are no portable, small device that will fit in a bag. There was one, an Edie Bauer product but it was pulled due to safety concerns.

Some feel it's better to "practice". I didn't. My first flight with a baby of 4 months was the 11 1/2 hours. Mine are often really good on the long flights but when we've flown a short distance, with my husband, they've turned into devils! One time, a week after getting back from California, we went to Spain and they were absolute horrors! What happened??

Short flights can feel a bit rushed, a bit like herding cattle and your baby might react.

So if your short flight (hope not but IF) is not a big success, don't let that put you off your next adventure. Kids can change from day-to-day!