Jax Remote Control lets you send commands to a remote host, which executes them immediately. Jax Remote Deskshot takes screenshots, either one time only or observing a screen over time, and uploads them via FTP or SSH.
With OGSS (Open Gmail SMS Shell), you can control your computer with SMS text messages. All you need is a cell phone and a Gmail account. OGSS uses Python and libgmail to fetch messages from your Gmail account and run the included commands on your computer.