Digital video cameras are smaller, more secure, and incredibly more sophisticated than their predecessors, putting out HD video, sensing motion, and sending alerts to your phone.
We love the Dropcam HD [$150; dropcam.com]. It's clear and simple to set up, and its two-way audio system lets you, say, discipline homebound pets from afar. Another option for your home's entryway is the Control4 Door Station [$2,200; control4.com], which can send audio and full-motion video to a number of devices. The only drawback? It requires pro installation.