(adsbygoogle = window.adsbygoogle || []).push({}); First you need to setup your Macbook to act as a wireless adapter. You can find instructions on how to do this You must login or register to view this content., or just read ahead. Follow these instructions carefully.
Mac OS X
1) System Preferences-->Network-->Built-in Ethernet-->TCP/IP
2) Set Configure IPv4: to Manually
- Set IP Address: to 10.0.0.1
- Set Subnet Mask: to 255.255.255.0
3) System Preferences-->Sharing-->Internet
4) Set Share your connection from: to Airport
- Set To computers using: to Built-in Ethernet
- Click Start and than Start

XBOX 360
1) While in the Dashboard, navigate to the System blade
2) Network Settings-->Edit Settings-->IP Settings-->Manual
3) Set IP Address to 10.0.0.2 ( The first three segments i.e. 10.0.0 will need to match what you set in step #2 of the Mac OS X section )
- Set Subnet Mask to 255.255.255.0
- Set Gateway to 10.0.0.1 ( What you set in step #2 under the Mac OS X section )
- Click Done
4) Go to DNS Settings
*** NOTE: I set the primary to my router and the secondary to my ISP's primary. You can find your router's IP by going to your MacBook and to System Preferences-->Network-->Airport-->TCP/IP
*** NOTE: You can usually find your ISP's DNS servers in your routers status page, see the manual that came with your router for more information.

Ok. Now that you have setup your Macbook as a wireless adapter, you'll need a simple program that records your mouse movements. (Note: This is optional. This just makes it so that you only have to click your mouse once to engage your lag switch.) The program is called Keyboard and Mouse Recorder. You can download it You must login or register to view this content.. Now to setup the lag switch. Open up System Preferences. Goto Sharing. Click Internet. Now, here is where the Recorder comes in handy. Start recording and click "Stop" on the sharing pane. The button should become "Start", click this button. You'll have a confirmation window pop up, click "OK" then stop the recording. Test out the timing and make sure that the recorder recorded everything. You may have to play around with the settings a little bit. Now from the time you pressed stop to the time you accept the start sharing there should only be around 5-8 seconds of delay. Now just press play when you want to lag and you'll have 5-8 seconds of lag. In my experiences this only lags everyone else when you're host. (Another Note: When you use your Macbook as a wireless adapter, your NAT will become moderate.)

Have fun lag switching.

What about ps3?

thanks i was wondering how to do this