The resistor-vga trick is one I use somewhat regularly. When traveling to give a talk, I sometimes like to practice my talk with powerpoint's "presention mode"

The resistor-vga trick is one I use somewhat regularly. When traveling to give a talk, I sometimes like to practice my talk with powerpoint's "presention mode" in front of me. You can't easily get that mode without a second monitor plugged in. I keep a single bare resistor that can be stuck into two holes in the VGA connector. I keep the resistor inside a folded slip of paper so it doesn't get lost, and the paper has a reminder on it too showing which two pins to connect. Works perfectly.