Add a new ssh authorized key to a remote host... in one single line

It’s a common task: “Please, add my public ssh key to that host”.

And I usually get the key, copied it to buffer, ssh to the remote host, cd .ssh and
finally I do a cat - >> authorized_keys and paste the key.

But you can do it in just one single line:

cat | ssh myRemoteHost "cat  >> ~/.ssh/authorized_keys"

That’s all!