Metasploit is one of the best database and a software that has a list of exploits for different softwares, nmap is the great network scanner tool and when we integrate Metasploit and nmap each other than we can create a wonderful combination that will really helpful in the process of penetration testing and ethical hacking.
Beside nmap we can also integrate nessus result into metasploit and this tutorial has discussed before but we got many comments and messages that postgresql is not working on Metasploit in Backtrack 5, so here is another video tutorial that will show you how to use postgresql server on Metasploit in backtrack 5.
The tutorial will also teach you about Metasploit autopwn by using nmap results. After this tutorial you can say that the problem of postgresql on Metasploit has solved.
Postgresql Metasploit Autopwn Backtrack Tutorial
For more about meterpreter you can see social engineering toolkit tutorial on backtrack 5.