Data detectors, something I use constantly in Mail on the desktop, are going to be system-wide in iPhone OS 3.0. Ars’ Chris Foresman:
Forstall also briefly mentioned some other API additions, including giving developers access to the iPhone’s proximity sensor, a user’s iPod library, streaming video and audio via HTTP (even through firewalls), system-wide Data Detectors (rumored to be coming to Snow Leopard as well), and even built-in VoIP APIs.