I have recently become aware of a plugin for Visual Studio called Ghost Doc. You right click on a piece of code and click "Document This" or alternatively I assigned ctrl + shft + D to do it for me. It is that easy, and boy is it useful. Nice and quick.
Download from : http://www.roland-weigelt.de/ghostdoc/
Some Examples
The context menu 
A property documented
OK, not completely there, but a total time saver none the less.
While I have complete respect for the person who made this plugin, it would have been nice to see it pick up on any exceptions which are thrown. When intellisense sparks off, I love seeing what potential exceptions could be thrown so I can code for any circumstance nice and cleanly. Again, as I say, this is a rally useful tool and I feel it is a great time saver!
UPDATE:
LOL I have unknowingly stumbled on a little cool piece of this plugin. Notice in my last screen shot I called it TestThisMethod. The documentation actually breaks that into a grammatical sentence "Tests the this method," which I have to applaud! WELL DONE GHOST DOC!! lol
Cheers,
Andrew