One of my favorite hacks is to "steal" data from other devices, like this Pioneer cassette player hack, and this digital caliper hack. This guy from Flashing LEDs did the same thing with digital multimeters. Most of them are built around the same chip from CyrusTek, the ES519xx series. This chip has a built-in function to transmit data over a serial port, something that most multimeters don't use. Read this article to learn how to unlock and how to acquire data from this chip, and connect your multimeter to your laptop.