Monitoring >> Discovery :
[List of discovered hosts ]
in column "Discovered Device" add function "exec script" ( from list as defined in [Administration/Scripts/ )
for example :
[Discovered Host....] ->EXEC

• [NMAP] ( code: /usr/bin/nmap -v {HOST.CONN} )
  * [SNMPWALK] ( code /usr/bin/snmpwalk -Os -c public -v 1 {HOST.CONN}

  system )

These two news calls are specially useful for me . Of course
many other scripts may be usefull ( PING ... / ARP / )

Reference Forum Request : http://www.zabbix.com/forum/showthread.php?t=22918

Janusz