Originally Posted by Jorgen

I'm typing this on a 27" iMac and... boy, it's big. Especially with that stand, I'm not sure if the top-to-bottom width is small enough to fit into an overhead bin. You should measure it carefully and contact the airline to see whether it'll fit.

It's heavy, too, much heavier than it looks, but afaik United don't have a maximum weight for cabin bags (presumably they reserve the right to complain if your bag is filled with lead bricks though).

I see no reason why the TSA would have any problem with it. It's just a computer, right? "Yes sir, my laptop is a little larger than most."