I have long been a fan of Dragon Dictate for the iPhone. It is a free app that will take your dictation and convert it to text and then save or send it as you like. Super handy when driving and you need to jot down your thoughts.
I recently discovered Dragon Go, the newest app in the lineup from Nuance. It is another FREE app from Nuance and it brings voice search and more to iOS and Android phones. Some reviews are saying it is better than the built in voice search on their Android phone.
You can have it launch Pandora on your phone, or ask for directions and it will search and launch google maps, or ask it to find nearby restaurants.
Of course, it has some limitations, and it is no Siri, but it is FREE and in keeping with Nuance tradition... the voice recognition is impeccable.
Take a look at this video from Nuance to get a feel for what it can do. Better yet, download it on your iPHone or Android phone and try it out.