for me it depends. my "small" dog, ended up being a bit taller than he was supposed to be (scotty) and so he doesnt fit in his carrier (at least not under the seat). if i can DRIVE he goes with me. if i have to fly he stays at home with a sitter. (in the end its not much more than a kennel). the cat stays home. the neighbor feeds him if i'm not around (and because he's manipulative... he's sometimes fed WHILE im home too!) its nice when they can stay home and have their daily rituals, and someone is there to water, bring in mail....and i require the sitter to sleep at my house. owen's never slept alone...

short answer. owen is with me or home, and clive the cat stays home. i wont risk putting owen in the belly of a plane.