Real estate search engine Trulia, which has lots of great content and features, has launched an API. So now anyone can tap their data. Here are two examples provided by the company: Plotornot and Truliaholic (modeled on Alexaholic).
This is part of a broader distribution strategy for Trulia, clearly hoping that its content and maps will be adopted as Google and Yahoo! maps have so widely been adopted by third parties.
Screenwerk 