Quick NPCs with depth

I think its a good idea to have a list of NPCs at hand that you can just grab and put into play at a moments notice. The problem in the past has been that the time sink of creating a stack of NPCs that may never see day light is risky. Some sessions all I'll have is a list of names and a list of "roles" that need to be filled. When the NPC shows up to play they rarely turn out as I expected, so no matter what I try to keep them fuzzy in score and broad in detail.

One of the problems with this is that my NPCs can then cycle through the same 3-4 characters with little or no variants between them. There are several tricks I'm eager to try in the near future, but my first step is to start getting a bare minimum of detail down for every NPC I'm creating. A good rule of thumb (and totally ripped off from C.M. Cline's article The 7-Sentence NPC published in Dragon Magazine) is to write down a few brief sentences that summarize the NPC in question. A good list to start with is:

1. Occupation and History - what do they do and how did they get to where they are today
   
2. Physical description - what things stand out and what will observant PCs notice
   
3. Attributes and skills - a general over view is all you need here
   
4. Values and motivations - how does the NPC see themself and where are they going
   
5. Interactions with others - sometimes it helps to imagine them talking with a young child, a greasy salesperson, a superior, a loved one, or an equal
   
6. Useful knowledge - everybody knows something, but limit this to things that could help the PCs
   
7. Distinguishing feature - don't limit it to physical, a voice or aura could come into play also
   
8. Distinguishing gear - weapons, armor, mount, eyewear, pets
   
9. Secret - not necessarily something the PCs need to know, but definately something the NPC doesn't want anybody finding out
   
10. Standard reaction to Players - how does this NPC feel about people who are of the PCs background, race, religion, nationality?
11. Famous Actor this NPC most looks like
12. Accent that this NPC will most likely have
    

See. Simple, direct, and with a stack of these short blocks in hand you can fill the lives of your PCs with deep and interesting NPCS.

Special thanks to Beau Yarbrough for the "Secret" for the NPCs since that is quite handy.