I think Android has it natively since 2.3 where you can find Voice Voice Input - Voice Recognizer.
Voice search with cantonese input is available from Android 2.3,it only works on the Search bar and within browser search..Not working on text field on other Apps.
=> Single session..the search starts right after the 1st sentence captured
Voice Typing -Continue to add translation till [Done] is pressed or buffer full.. you can take your time to say sentence by sentence,it will keep adding the new sentence .
Voice typing is glued o the ICS Stock Keyboard. Default setting for voice typing is automatic,however there seem to have bug..this automatic setting doesnt understand cantonese or any other language other than English.
Change the Stock Keyboard -Voice typing setting, to manual select a few languages that you like to use Voice Typing
Go to setting\Language&Input\Voice Typing, deselect the default 'automatic' to other languages.
Cantonese ,Yue (Hong Kong ,Traditional ) is for Cantonese voice typing