Siri has definitely been a game changer in the world of voice control on mobile devices and there are many similar apps being developed for other platforms.
I have recently come across a great app for Android called Maluuba which offers a number of Siri style functionality but also a lot more.
Maluuba can be downloaded from here http://www.maluuba.com
The interface is clean and simple to use and I was particularly impressed with the tiles on the explore tab. Integration into calendar and social network functionality is slick and worked well.
The voice interpretation is reliably accurate and generally understands my accent!
Maluuba is definitely an app that will be one of my favourites and offers excellent functionality.
I will post a more detailed review later.