Enter: movies [film title] or movie [location]
Get movie showtime info.
Enter: weather [city or ZIP Code]
Access four-day forecast.
Enter: Ticker Symbol
Access current stock price (delayed) for NASDAQ, AMEX, and NYSE listed companies.
Other shortcuts listed here.
If you don't have an XHTML-capable mobile browser or just want to check out the mobile service, the user interface should is accessible here.