Thanks for the replies everyone. I also emailed Delta and Continental, and their replies were far from helpful - when prompted a bit further Continental said as long as it can fit under the seat in front, it can be brought on as a personal item.
So I'll keep my 2 carry-ons relatively small, I can't see myself needing too much.
And Greg, that site is awesome, turns out I get 2 free checked bags on my HA flight home
