Linux hardware info

$sudo biosdecode
$sudo dmidecode
$sudo dmesg
$sudo cat /proc/cpuinfo
$sudo cat /proc/meminfo

Get Information About Your BIOS / Server Hardware From a Shell Without Opening Chassis ( BIOS Decoder )

List open ports – netstat

netstat can be used to list all open ports on a machine

Linux

$ netstat -an | grep -i listen
Command options will be different in diff version of linux

Windows

> netstat -a | find /i "listening"
> netstat -b     //will show the process names
> netstat -?

Some links on the web
http://blogs.techrepublic.com.com/security/?p=443
http://www.petri.co.il/quickly_find_local_open_ports.htm