SMS05 TVS 4 Array-Unidirectional 6V 350W SC-74 SMS05T1G

I bought these for protecting data busses connected to risky hardware (salt-water aquarium stuff). Good for SPI, UART, or anything you can think of really that runs signals at 5V or below. My use is for a SPI bus that links devices that are at risk of high voltage transients.
Not sure if these would help much in the case of lightning, but extra protection never hurts if you're building something for yourself. A lesson I've learned is not to go crazy if you intend to market a product. Half of electrical engineering is holding back the part of yourself that wants to do everything 100% "right" as to keep the final price of the device marketable.
Tayda also sells MOVs and higher-power TVS diodes for combined protection. An array like this would go very close to the device you're protecting and SHOULDN'T BE the first line of defense if you expect dangers like lightning or inductive kick-back.
I've also seen these protecting interfaces like HDMI, such as on the raspberry pi.