Minecart Connecting

Using minecarts can be annoying if you want to use it to store any useless items you gain from a mining trip, or if you wanna build a roller coaster, there's no way to have more than one minecart connected together to have multiple riders at once. What if there was a way to connect minecarts? Maybe we could use leads to connect them together, or maybe there could be a new item that allows minecarts to connect. Maybe it could incorporate copper so that it finally has a use.