Mad Priests on Madmortem

Impressed?

Ok, enough showing off, here is what might help you get your latency down by a two-digit percentage:

A. Vista Autotuning: This will only make sense if you run vista. Really. Actually it will disable a feature that is supposed to improve bandwidth on highly used connections by reducing the amount of control flow. This might reduce your throughput i.e. when copying files on your local network or downloading larger files from the internet.
In an elevated command prompt simply type or copy and paste (pasting in a command prompt works via right click->paste):
netsh int tcp set global autotuninglevel=disabled

B. TCP Ack Frequency: TCP (Transmission Control Protocol) numbers all data packages that exit your computer. To confirm that a package was received, the other side sends a so called ACK package (from acknowledge) to inform the sender, that everything up to a certain number of packages was received.
Example:
Sender: Sends packages 1-5
Receiver: Receives packages 1-2 and sends an ACK for 2, receives 3-4 and sends an ACK for 4.
(5 was lost)
some time later the sender just resends 5, because it never got ACKed.
Now, the receiver in our example used a tcp ack frequency of 2 - he received 4 packages before sending his ACK - actually this is totally acceptable behavior and reduces the amount of useless garbage on your lines.
In the example, the receiver used the same TCP Ack Frequency that Windows uses – a very good compromise for most situations. However, World of Warcraft depends more upon fast answers than a high throughput, so lowering your tcp ack frequency can very probably reduce your latency – for every second package.

To do so, you first need to determine your IP address for the given network adapter using ipconfig or a similar tool. If you are unable to definitely determine the ip address of the network adapter used for playing world of warcraft, do not continue!
After this, open a little program called regedit by typing regedit into your vista start search (the text box which is in your start menu) and hitting Ctrl+Shift+Enter to launch it elevated. Browse the folder structure on the left as you would browse your local folders.
Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces.
In this folder, there are several subfolders which all wear cryptic names, and you will need to identify by browsing into the interfaces and searching for the ip you noted in step one. As soon as you managed to identify the wanted interface, look for a key called “TcpAckFrequency” – if none exists create it by hitting Edit->New->DWORD (32bit) VALUE (this might be called slightly different in your regedit, but it will always contain DWORD) and creating this value.
Now edit it to be “1″.

REVERTING A. Vista Autotuning:In an elevated command prompt simply type or copy and paste (pasting in a command prompt works via right click->paste):
netsh int tcp set global autotuninglevel=enabled

REVERTING B. TCP Ack Frequency: Edit the TcpAckFrequency to “2″ or simply delete it.