Apple's Siri voice-command feature isn't exactly flawless on the iPhone 4S, a shortcoming that points to the limitations of today's speech recognition software. But when Siri works well, it's both helpful and fun. Android users can acquire a degree of Siri-style functionality with Google's Voice Actions for Android, which performs a specific set of vocal commands, such as "map of [address/city]" and "go to [website]." For a natural-language experience (i.e., more Siri-like), try Speaktoit Assistant, a free "virtual buddy" that answers questions, finds information, launches apps, and so on. And Vlingo, another free virtual helper, is handy for sending texts and emails, and updating your status on Facebook and Twitter.