Can I get an earlier connecting flight? Also, ESTA?

Question

It's still some time away yet and I know flight times can change but I have been looking at some flights to the US. From my connecting stop to my destination there is about 2 and a half hours time gap. The last time I went though this same route the last time I flew out and going through customs and the security check was quick, so I may have a wait on my hands. If there is an earlier flight (its a short distance/small plane flight) to my destination, is it possible to get on one or will I really have to wait until my booked flight?

On a side note; how or where do I go about applying for this new ESTA the US are doing now?

Answer 1

If you get to you connection airport and realize you will have to wait a lot for your booked flight, you can find out if there is an earlier flight. It that's the case, find the gate and ask the person in charge if they will let you get on that flight. I have done this before and most times they have let me do it if they  have seats.