If you have an extra phone lying around using android there's an ip camera dvr program, so you can hide the phone somewhere within range of the router and it'll record all of that. Not only will it be recorded but you can also access this camera from anywhere with an internet connection including a cell phone. I own a foscam ip camera, really impressed with it. Mines the indoor model, but the outdoor models can be had for under $100 a pop. I have mine setup on a schedule, so when i'm not home it turns on the alarm and if movement is detected it sends me an email. I get a few false alarms in the living room due to sunlight but other than that its pretty solid.