Great ideas on this thread, however.....
If you have really valuable jewelry, family antiquities, etc, they should be stored off-site in secure facilities when you leave town. The rest is just stuff.
Cameras and DVR (et al) may allow to police to possibly persue the perps. The perps, if ever caught, have already pawned/sold the goodies, usually plead out, and you are stuck dealing with the insurance company. In any case, it is an insurance thing and putting really valuable things in secure places.
Dont give them a chance to get the good stuff!