OT: Network setup - NAT

[Hiisi]

Dear Fedora crowd!
I've a desktop running Fedora 10 connected to the Internet via LAN. 
There's 3 network controllers in the desktop. One integrated to the 
motherboard and two additional. I would like to connect other computers 
(two laptops, one running fc9 and the other Window$ XP) to the Internet 
via the desktop. I googled the question and found out that I need to 
adjust thing called 'NAT'. For that purpose I did the following:
iptables -t nat -A POSTROUTING -s 192.168.2.0/24 -j SNAT --to-source 
192.168.*.* where 192.168.*.* - is desktop' IP address. I want to use 
192.168.2.0/24 as a network for laptops. I activated one of devices 
(eth1), gave it IP address: ifconfig eth1 192.168.2.0/24 and connected 
f9 laptop to it. On the laptop I activated eth0 with the same IP. The 
problem is: it doesn't work. I can't ping anything from the laptop 
except its own address (192.168.2.0). What should I do? Any help will be 
appreciated.
Thanks in advance.
--
Hiisi.