You can use rlogin in an existing Terminal window to log in to a remote host. Once the window is acting as a terminal to the remote host, you can run applications there, redirecting the display back to your system if you desire.
For example, the following command logs onto a system named there, runs the client xload, and redirects the display back to your original system. Assume your system is named here.
rlogin there xload -display here:0