LAN Network Discovery

Hi,

I am looking at making an app in C# that is able to find all network devices on my LAN and get there current IP and MAC Address. I have multiple devices that can connect to the LAN.
Multiple PC's, Laptop, WII, XBox, PSP, NAS, Phone, Kindle.

I would like the output like so:
192.168.1.1 : 00-0C-F1-56-98-AA 
192.168.1.100 : 00-0C-F1-56-98-AB 
192.168.1.101 : 00-0C-F1-56-98-AC
192.168.1.102 : 00-0C-F1-56-98-AD 
e.c.t.

I started by trying to ping from 192.168.1.1 to 192.168.1.254 to find the IP's which replied. The problem is that some of these devices dont seem to reply to ping, and just timeout.

Does anyone have any other suggestions on how I should proceed?

Jay