There have been various hacks that make Siri do extraordinary things and now Vocal is here to make Siri, control and drive your Mac.
With Vocal, you can use your iPhone 4S to control apps, perform searches, copy and paste text, control iTunes and do many other things.
Matthew Roberts who created Vocal as a project explains:
Vocal came essentially from playing with Siri on my new 4S as a sort of “novelty” as I just acquired the device, and since I use my Mac so much I wanted to see if I could write a Siri-like app for it. After looking around the only main competitor was the software from Nuance, but it was over 1GB to download and cost upwards of $50. Considering the 4S can already dictate text, I thought I could make a super simple app “for the masses”, I guess you could say.
Vocal pipes commands made with Siri dictation to your Mac through a WiFi connection. The Vocal software in Mac can give voice control abilities to Alfred app.
Source: Cult Of Mac