Archlinux now supports networkmanager thanks to Tor Krill. It is all based of his packages.
How to install:
for Gnome: pacman -S gnome-network-manager
for KDE: Go to the aur and build : knetworkmanager-svn
Configuring your system for networkmanager:
networkmanager does parse your /etc/rc.conf, to see if you want to have a static or dynamic ip on your interfaces. Disable interfaces with ! in front of it if you want to use it with networkmanager. My interfaces line looks like this: INTERFACES=(lo !eth0 !ath0)
So just put in your prefered config into it.
example for static:
eth0="eth0 172.19.3.18 netmask 255.255.255.0 broadcast 172.19.3.255"
example for dynamic ip:
then add dhcdbd and networkmanager to your deamons array and restart your system. You can also manual get rid of any dhcpcd processes and start dhcdbd and networkmanager manual.