The best speech recognition application on the Mac, MacSpeech Dictate, got updated today to version 1.3. Now you can use MacSpeech Dictate in any document, including those that were not created with MacSpeech Dictate. There is a new "Cache Document" command that allows MacSpeech Dictate to read a document's contents, in order to navigate the document, and to enter and edit text.
MacSpeech Dictate uses a cache to keep track of the text in the window and where the selection or insertion point is located within that text. This is a significant improvement for this application. I routinely use both MacSpeech Dictate and DragonDictate on the PC side. MacSpeech Dictate still has a ways to go before it gets the functionality of DragonDictate but the aggressive updates and improvements are encouraging.