Can't remember who it was, but saw this in my e-mail today.
They made an announcement about a new product at the consumer electronics show going on in Las Vegas this week about being to discern between non-events (dog walking by) and real events (robbers, vandals, etc...) and I thought I remembered someone here at one point looking for a wireless monitoring system similar to this. Have no experience with them, but thought I would pass along.

http://www.myarcherfish.com/