Thanks for so many awesome replies! I have been thinking about an Australian Shepherd - I've always wanted one. They are incredibly smart, and have a lot of energy. The plan would be to bring the dog with me to the flying field every time, and maybe play fetch between flights. They have those 'tennis ball thrower' things that let you launch a ball pretty far so the dog can run a lot. Aussies are typically easy to train and are not agressive if trained.

Obviously getting a dog is a huge decision and commitment, so I'm going to take my time on this one. But I temporarily moved into a place with an Aussie (and a blood hound) and absolutely love this guy. I am excited to see him in the mornings and evenings, and I've only known him for 2 days now.

So they are 'medium' size dogs, 50-70lb and 20-23in at the shoulder, supposedly. Not the smallest dog in the world, but not huge. The trailer idea sounds great since I drive a small truck, and really liked the trailer I saw at Site 4 at the Nats this past year, with the AC and stuff.

I am going to try to meet some other Aussies and talk to their owners to see if it is a good fit - not sure how 'demanding' the dog would be and how much it would impact flying/building/other hobbies, although I have really been in need of a good walking partner.