A while ago I set up a Raspberry Pi as a webcam monitoring my front door. It is able to record and send the movie to Dropbox, motion activated.
Works very well and is necessary because I work in the basement and would miss visitors/deliveries otherwise. Also, I like to know to ignore the door if someone is selling something.
One thing that bugged me though was the commercial product for this worked but was too big.
10 mins with illustrator and my laser cutter and I now have a solution that fits perfectly.