Binary

This stylish looking mat is really just the phrase 'welcome' encoded in binary. So, in a way, it's a dual purpose device. Your UPS delivery guy is going to think it's just a cool, funky, retro pattern. And he'll be right. But your uncle from NASA will see that pattern as a collection of seven other patterns at which point he'll quickly decode the message, chuckle, and slap the knocker on your door.