A good source where I get a heads up is by doing BPO's. They can be an indicator a month or so sooner that a NOD.
I buy data from a company in Tampa. It's not 100% accurate but I'd say it's 80%. Have had good luck with them. I don't have their info with me now but you can email me tomorrow and I'll forward it to you.
I have found that here in Arizona, Title companies often have this information. They have resources in which they can extract it from.
Your favorite Title Company. Depending on the laws of your state, you may need to pay for it such as Texas and California. The cost is minimal. They provide a treasure trove of information in the reports.
Title companies only have once NOD is filed in Nevada.
I shot you an email. Thanks Ben...it's greatly appreciated.