There was a brief period during the late 90s/early 2000s before WiFi became ubiquitous that laptops came with IR transmitters/receivers for streaming data. It

There was a brief period during the late 90s/early 2000s before WiFi became ubiquitous that laptops came with IR transmitters/receivers for streaming data. It was always touchy, slow, required an unbroken line of sight, and poorly supported by both the OS and application software, but I did make it work a couple of times. The PDAs of the time used a similar technology to send contact information (business cards) between devices.