I have a great distance from my gas water heater to my bedroom bath because I had to move it to an attached garage location. I seem to have to run the water forever before it gets hot and it seems like such a waste. Is there a way to recycle the water until it gets hot, or possibly put a pre-heater on the line to warm the water until the water from the heater kicks in?

You can install a brass circulator to have the water continiously circulating and hot.