I would like the physical address of the Neopets headquarters that is
located in California where their employees are at...not the P.O. Box,
but their physical address where gifts and packages can be delivered.

Hello.

Neopets' physical address is 412 West Broadway, Suite 303, Glendale, CA 91204.

From neopets.com:

NeoPets, Inc.
412 West Broadway
Glendale, CA 91204
http://info.neopets.com/presskit/articles/recent/charity_auction.html


Also see this web page cached by Google:

"something that is hard to get: The NeoPets Inc. headquarters address!
412 West Broadway Glendale CA, Suite 303"

source: nataliehanley.com, cached by Google:
http://66.102.7.104/search?q=cache:FTOHjylXLQkJ:www.nataliehanley.com/neopets.htm+%22+neopets+inc+%22%22headquarters+address&hl=en

--------
search strategy:
"neopets inc" "headquarters address"
neopets broadway glendale

I hope this helps.

Also it appears they have mroe info in thier domain registration that
migh be of help:

   NeoPets, Inc.   
   P.O. Box 10263 
   Glendale, CA 91209-0263  
   US  
     
   Domain Name: NEOPETS.COM  
  
   Administrative Contact , Technical Contact :    
   NeoPets, Inc.   
   legaldepartment@neopets.com  
   P.O. Box 10263 
   Glendale, CA 91209-0263  
   US  
   Phone: 888-200-8090  
   Fax: 818-956-3855  
 -------------------------------------------------

Also, googling their 800# gives you several interesting articles:
  http://www.pressreleasenetwork.com/pr-2000/november/mainpr380.htm
  http://findwealth.com/green-dot-capital-signs-mou-923073pr.html

The question specifically requested a physical address rather than a
post office box.  As indicated in my answer, the physical addresss is
412 West Broadway,  Suite 303, Glendale, California.