TUAW reader Harris Rydal sent in a bunch of terrific suggestions for using Siri's built-in search features without having to do a lot of typing. These are exceptionally useful ways of taking advantage of Siri-to-Safari tasking.
Sports scores - Look up the current score for in-progress games and find the team record, last game score, and the upcoming game. Say "Yahoo team name score". Rydal points out "There is a 'Yahoo' here because mobile Yahoo formats the results better than Google."
Flight Times - Say "Search the web for flights from City/Airport to City/Airport". In Google, this brings up a list of flight times that day and the associated airline.
Movie Times (and Ticket Purchasing) Say "Search for Movie Name showtimes Optional ZipCode", or if Siri will let you, you may get away with simply "Movie Name showtimes Optional Zipcode". You can also "Search for showtimes Zipcode".
Rydal points out that if you've set Google in Safari to use your current location, you don't even need to specify an area code. Google's Fandango integration allows you to click the showtime and hop over to the ticket purchasing page.