I have Repetitive Strain Injury, so I use speech recognition a lot. I think the speech recognition in Windows 7 is great, although I miss some things in it.
For those who also have RSI, or just want to use the voice, I found two add-ons that I think is pretty interesting.
The first add-on is the Windows Speech Recognition Macros, you can group several speech commands at once with it. The only drawback is clicking anywhere on the screen with your voice. Windows default "mouse grid" takes a lot commands to move and click. For this issue, I found another add-on for clicking anywhere that is pretty fast. It is a tiny add-on called Voice Finger (http://voicefinger.cozendey.com), and by the way I'm using it right now.
For those who are sick of the WSR "mouse grid", I think this is good news.