[AccordionGuy]

I've never had a problem with carry both an accordion and a knapsack containing my laptops. The accordion I travel with fits handily in just about every aircraft's overhead compartment, which certain simplifies those rare moments when the flight crew gives me static about not checking or gate-checking it.

I agree with the author that getting on the plane early is important. Another good trick is to try and get seats near the rear of the plane, as many (but not all) airlines try to board the plane from the rear seats first. This gives you a better shot at getting space in one of the overhead compartments.