I was showing off Google Now Commands to my team a few days ago and the biggest pro-iPhone user in my team picked up the phone and asked Siri if the Broncos were going to win that weekend. Yeah, it popped by balloon for sure. I decided that I needed to get great clarity on all the potential commands that DO WORK for Google Now.
If you have Google Now you can use voice commands. Check the settings icon in the Google app and you can select if you want to be able to activate the voice command from any screen or just in the Google App. You can also record your own voice a few times so that it will (in theory) only recognize your voice when you say, “Google Now.”
After checking some other websites I found the most complete list on Greenbot.com. Here it is:
How old is [Neil deGrasse Tyson]?
Where was [Louis C.K.] born?
Define [colloquial] (Or “What does [colloquial] mean?”)
What time is it in [Tokyo]?
Search for [photography tips]
Show me pictures of [the Leaning Tower of Pisa]
Do I need an umbrella today? What's the weather like? What's the weather in [New Orleans] [this weekend]?
What the [Google] stock price? What is [Apple] trading at?
What's [182 yards] in [miles]? What is [12 ounces] in [liters]?
What's  divided by [7.5]? (A great many types of math equations will work.)
Take a picture (“Take a photo” also works)
Record a video
What's the tip for [123 dollars]?
Set an alarm for [6:30 am]
Set a timer for [20 minutes]
Create a calendar event: [Dinner with Glenda, Saturday at 9pm.]
Remind me to [buy coffee at 7am] (try locations! Remind me to [buy coffee filters at Walgreens])
What is my schedule for tomorrow? (also: What does my day look like [Friday]?)
Where's my package? (tracking confirmation must be in Gmail)
Make a note: [update my router firmware] (also try “Note to self:” This works with multiple apps, and you can even email yourself!)
Find [Florence Ion's] [phone number] (Works with all info in your contacts – addresses, birthdays, etc.)
Call [Jon] (also works with relationships: Call [sister])
Text [Susie] [great job on that feature yesterday] (also works with relationships: Text [mom] [I'm not going to be able to pick you up from the airport, period, I'm a bad son, period])
Send email to [Robert Baratheon], subject, [hunting], message, [I don't think you should drink so much when you go hunting, period]
Post to [Twitter]: [Oh my god the Red Wedding episode!]
Navigation and Travel
Where is the nearest [sushi restauraunt]?
Navigate to [Willis Tower, Chicago]
Directions to [Fisherman's Wharf] by [bike] (also try “Directions home” or “How do I get home?”)
Where is [the Louvre]?
Show me the menu for [Green Chile Kitchen]
Call [Asian Art Museum]
Show me my flight info
Where's my hotel?
What are some attractions around here?
How do you say [good night] in [Japanese]?
What is [50,000 yen] in [dollars]?
What's the flight status of [United] flight ?
Show me restauraunts near my hotel -or- Give me directions back to my hotel (this works if your hotel confirmation was sent to your gmail account)
Play some music (opens “I'm feeling lucky” radio station in Google Play Music)
Next Song / Pause Song
Play [Happy] (songs must be in Google Play Music on your device)
Watch [The Lego Movie] (movies and TV must be in your Google Play account)
What's this song?
Listen to TV
What songs does [Pharrell] sing?
Read [Hunger Games]
Did the [Giants] win today? What's the score in the [Warriors] game?
What movies are playing [tonight]? Where is [Toy Story] playing?
Fun hidden stuff
Many of these deliver funny voice responses, but normal search results. Turn up your sound!
What is the loneliest number?
Do a barrel roll!
Askew / Tilt
Go go Gadget [Spotify]
When am I?
Make me a sandwich
Sudo make me a sandwich
Who's on first?
Up, up, down, down, left, right, left, right
Tell me a joke
Who are you?
Beam me up, Scotty!
What is [Jennifer Lawrence's] Bacon number?