Not a bad idea...I'd love to have goats some day. They are supposed to do a great job on the grass, unlike sheep who pull it up by the roots.
Someone I know who grew up on a "gentleman's farm" had goats that would go places in the car with them just like the family dog. Another person I knew who had the same kind of farm had goats that were also like dogs....they followed you around and wanted you to pat them and stuff.
I've got friends who keep their yard tidy with pygmy goats--and there's a "rent a goat" operation out here. I've been tempted, but I'm afraid that the dogs might not like the attention that the goats would get.
But goats will eat just about anything that's lower than their eye level, including poison oak, blackberry bushes, fir seedlings...