Thanks to Amit Agarwal, I discovered that you can easily add a speech option to any input boxes that you have on your website inlcuding your search box.
Unfortunately, it only works with Google Chrome at the moment! But, as Amit explains it can also be used with a textarea. Here you can add longer sentences. If you are building up a paragraph, then the text must be copied to another location as the text area is cleared each time the microphone is activated. Could work well with short answer questions for those who struggle with typing text. A free and easily implemented option.
Works fine with Blogger, Wordpress and Moodle. Now, if only there was an easy way to add this option to Google Docs forms :)
Why not try it out below:
Click the microphone icon and speak
Remember, you must be using Chrome!