Is there a departure tax at Quito Ecuador International airport?

Yes, depending on where you are heading.

Domestic, it's about $6 USD (changes due to currency)

International is about $30 USD (some sites say $28, some $32.25)

I just came back today, Jan 2, 2010 for my wife and I who had continental tickets, we had to pay $31 each, and... $31 for our 8 month old daughter.

This was not included in the ticket we had to pay it at the airport before boarding.

This is apparently differnent formt he $15 Tourdist Fee which was included in the ticket.

My mom was with us but flew Delta and her $31 departure tax was not included.