Windows expert Deb Shinder has been chatting with Vista lately--and Vista has been listening.
Once she got past the desktop microphone fiasco and opted for a headset, and once Vista learned to interpret her Texas accent, Deb had good success piloting the OS and various programs--as well as dictating text--using Vista's built-in speech recognition capabilities.
In "Speech recognition in Windows Vista," she describes how to configure speech options, set up your microphone, and train the speech engine to recognize your pronunciations. Then, she explains how to issue voice commands ("Sit!" "Stay!" "Tab!"), access help, and dictate (and correct) text.
Her assessment: "I was impressed with the ease of use and accuracy of the Vista speech recognition engine after half an hour of training time. I've tried dictation programs before and never found them at all usable; I could always type much faster than I could dictate and correct text. Now I finally feel that if I should ever lose the use of my hands, there would still be a way for me to continue to get my work done."
She concludes with a caution, though: Speech recognition brings with it a security concern involving unauthorized speech commands coming from malicious sound files. It's a stretch, but the risk does exist. Still, you should be able to avoid any potential exploits by making sure the feature doesn't start automatically and by turning it off when you aren't using it (as opposed to letting it hum along in Sleep mode until it hears the words "Start listening"--sort of like a 9:00 AM art history class).