I have been an independent consultant for 12 years. I have a master services agreement/NDA that has slowly evolved over time, often adding something to get a gig.

Feel free to use mine (http://markwatson.com/consulting/nda.htm) but if you improve it, please share your changes back with me.

After just re-reading my own doc, it is probably too long. It used to be about half this length.