via http://atmac.org/iphone-voice-commands
Phone Commands
Call a contact
“Call” or “dial” plus the person’s name or nickname as entered into your address book. Optionally add the phone number type at the end, such as “home”, “work”, “mobile”. For example, “Dial John Smith Work” or “Call Mum”.
Call a number
“Call” or “Dial” plus the number, just as you would recite it usually. For example, “Dial 555 9592″.
Make a correction
Say “not that one”, “wrong”, “nope”, “no”, or “not that”.
Music Commands
Start music
Say “play” or “play music”.
Play from a specific playlist
Say “play playlist” and the name of the playlist. For example, “Play playlist gym songs”.
Play from a specific album
Say “play album” plus the name of the album. For example “Play album Dark Side Of The Moon”.
Play from a specific artist
Say “play artist” plus the name of the artist. For example, “Play artist Pink Floyd”. The alternate “Play songs by” plus the name of the artist has also been reported to work.
Pause music
Say “pause” or “pause music”.
Skip to next song
Say “next song”. The shorter “next” has also been reported to work.
Go back to previous song
Say “previous song”.
Shuffle the current playlist
Just say “shuffle”.
Turn on Genius feature
Say “Genius”, “play more like this”, or “play more songs like this”.
Get information about the current track
Say “what’s playing”, or for more specific information say “what song is this”, “who sings this song”, or “who is this song by”.
Misc Commands
Ask the time
Say “what is the time” or “what time is it”.
Cancel voice control
Simply say “cancel”. With iOS 4 you can also say “stop”.
Get help
Say “help”.
Best Answer
The Reminders application does something similar, it knows three locations: Home, Work, and Other. When you assign a location to a reminder, you are presented with the current location, those 3 previously mentioned locations, and a "Choose Address" option. The 3 locations are taken from the address book's contact information for yourself. The contact that represents yourself is determined by the setting under
Settings>Safari>AutoFill>My Info.I'm guessing that Siri uses the same
My Infosetting to determine locations such as Home.Note that the name of a contact has no effect on the Reminders app. Even if you have a contact named "Home" it will not present this as a default address unless the contact is also assigned to the
My Infosetting.Update: Siri has its own My Info setting which is the exact same one accessed in Safari (i.e. they always have the same value).