When I ran across the book above today Halter Goats Book it reminded me of the photos I saw as a kid, with dogs pulling carts in the Netherlands, and also other rural areas. There's also Zonkers!
Cool stuff for sale here, photo from Fidogear.com
And then there's Skijoring!
From BozemanDailyChronicle.com Great shelter dog program there!
Think of the things you could do with 4 legged friends and some training!