Insulating the pipes will help save some energy, but I agree it's not
going to solve your problem. They do make recirculating pump gizmos
that will either keep it hot all the time or that have a button you
push when you expect to want hot water. They pumps are located near
the point of use and return the water back into the cold water line, so
it doesn't go down the drain. I think the push the button models may
also get the water there faster than running it down the sink, because
the pump pushes the water faster than pressure through the faucet would.