Learn how to create a DIY audio guestbook for weddings and events in this comprehensive tutorial. Convert a telephone handset into a recording device for guests to leave messages using a Teensy microcontroller and audio shield. Follow step-by-step instructions on identifying telephone components, wiring the system, installing necessary software, and programming the Teensy. Discover how to load and convert recorded messages using Audacity and SOX. Gain insights into cost-effective alternatives to expensive rental options, with a complete breakdown of required hardware and software. Perfect for those with basic electronics and coding knowledge looking to add a unique, personalized touch to special occasions.