I'm interested in hearing any opinions and experiences with specific models of home security systems, particularly camera based units. I definitely want to be able to monitor it over the web and, ideally, over my iPhone. I think I'd be fine with simply having something with a few sensors (like knowing if someone comes down the driveway) and 2 to 5 fixed cameras.

On a related note, I have a complete ADT system in the house with motion sensors and the whole deal that is currently not monitored. I have to believe there is a way to "tap" into the system at the main box/brain without using ADT. I'm not set on necessarily doing this but it just seems that if there is a way to take advantage of all of the existing wiring and sensors that I might as well use that to my advantage.

Thanks,
AP