Binary Fortress has launched VoiceBot, a macro manager for Windows Vista+ which allows you to control games and other applications with spoken commands.
At its simplest, you might have VoiceBot recognize the word "New", then issue the command Alt+F > N. Quick, easy, and works almost everywhere.
But if you need more, you can make use of commands to hold keys down, release them, move or click the mouse, spin the mouse wheel, play sounds, type text, convert text to speech, run lengthy scripts, even create extended macros with the built-in C# code editor.
If that sounds too much like hard work, VoiceBot offers easy access to "profiles", custom sets of voice commands created by other users.
The current profiles are almost entirely for games, with one or two exceptions (a Chrome profile supports commands like "New Tab", "Next Tab", "Open Homepage" and so on), but if the product takes off we expect this to change rapidly.
The program is available in a free-for-personal-use version, but this has some serious restrictions: no macro scripts, no text-to-speech, only three actions per macro allowed, and a maximum of five profiles.
Installing VoiceBot gets you a 30-day trial of the full version, though, and if it works for you then the purchase price seems reasonable at $9.
VoiceBot 1.0 is available now for Windows Vista and later.