I finally found the solution to my problem with getting 404 on static
assets (/images, /js, /css).

Not sure how I missed it before but I saw the problem in the error log
now. Basically I was not understanding that the root path needed to be
relative to the location of the nginx.exe (c:\nginx\nginx.exe).

Changing "/cygwin/..." to "../cygwin/..." was my solution. I didn't
have a problem with the non-static stuff (PHP) because all of that was
handled by fastcgi, which expected the full windows path
("c:/cygwin/..."). Below is my working config.

server {
listen *:80;
server_name jobsite.xpdesktop;

access_log logs/jobsite.access.log;
error_log logs/jobsite.error.log;

root ../cygwin/home/Chris/www/live/jobsite/trunk/html/public; # this
was the fix
index index.php index.html;

# serve static files directly
location ~* ^.+\.(jpg|jpeg|gif|css|png|js|ico|pdf|zip|tar|gz|bz|bz2)$ {
}

location / {
fastcgi_pass 127.0.0.1:9000;
fastcgi_param SCRIPT_FILENAME
c:/cygwin/home/Chris/www/live/jobsite/trunk/html/public/index.php;
fastcgi_param QUERY_STRING q=$request_uri;
include fastcgi_params;
}

location ~ /.php$ {
fastcgi_pass 127.0.0.1:9000;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME
c:/cygwin/home/Chris/www/live/jobsite/trunk/html/public$fastcgi_script_name;
fastcgi_param QUERY_STRING q=$request_uri;
include fastcgi_params;
}

location = /css/style.php {
fastcgi_pass 127.0.0.1:9000;
fastcgi_param SCRIPT_FILENAME
c:/cygwin/home/Chris/www/live/jobsite/trunk/html/public/css/style.php;
include fastcgi_params;
}
}