Project Knock is my first personal hardware project after a long time. I haven't actually begun putting together the hardware right now, because it's not arrived yet. Waiting on UPS to deliver stuff that I ordered from Digikey. I am going to be doing it on AVR (no surprise there), ATTiny2313.
I've created the repository and I intend to create the server on Ubuntu. The client is going to be Mac OS X 10.9 for now. Both, my roommate and I always have our headphones on and we miss most of our deliveries because we can't hear if anyone's knocking. So this is the solution. To get notifications on our Macs when we are working. Win.
The project repository can be found here https://github.com/DarkSector/knock
Here's the developer log for the whole project