Finding web servers with nmap

[Denis <da_shestakov () myrealbox com>]

Hi,

I have a task to "relatively quickly" find all web servers (all hosts
with open port 80) in some particular network. It seems it can be done
with the nmap program. Could you advice me concerning the best options
for running nmap to accomplish this task? In particular, does the
following command do it right?
nmap -v -sS -PS80 -PA80 -p 80 -oG my.log -iL x.x.0-255.0-255
I am asking that because I have a concern that the above command may
miss some hosts. However, it works faster than the command with "-P0
-p 80" ... 

-- 
BR,
  Denis