My wifes black MacBook does not support the new wireless N spec, and she can not really utilise the speed of our home wireless network - until I saw this :

Product Description:
Works With:
RangeBooster N Router
DIR-625
Xtreme N Gigabit Router
DIR-655
EXCEPTIONAL PERFORMANCE
The D-Link RangeBooster N® USB Adapter (DWA-140) is a draft 802.11n compliant wireless client for your desktop or notebook PC. It delivers up to 12x faster speeds* and 4x farther range* than an 802.11g network while staying backward compatible with 802.11g networks. Once connected, you can share a high-speed Internet connection, photos, files, music, printers, and more.

I seem to have hit a small problem with my wife's black MacBook - I am unable to upgrade the operating system/wireless card firmware to work with 802.11n.

I ran Apples 802.11n updater (which came with the new Airport Extreme base station) and it worked perfectly with my MacBook pro - as seen in Network Utility :

and in System Profiler :

But my wifes Black Macbook is not behaving. The installer runs ok - but in Network Utility

the adapter shows up as “802.11 a/b/g” - i.e. no “n”.

This is not in any of the documentation - but if you want to set up the O2 wireless ADSL router that they supply with all new ADSL subscriptions then you need to navigate to it's administration pages by going to http://192.168.0.254 with your browser (make sure your Mac has a IP address in the 192.168.1.x range) - this should bring up the following screen

(click for larger image)

The choose : Setup

Make sure you have the setup information that O2 sent you prior to shipping the box, and key in this information.

Btw. if you choose to use the wireless interface to do this - then the password is on the inside of the CD cover...

If you have a O2 wireless router at home, and want to run a Mac as a server for your own use, including a webserver, email, ssh and a VPN tunnel then this is the setup you need for the security setup :

You can (if you have just one server of course change some of my setups.

The IPSEC - IKE for your VPN tunnel

plus the IKE NAT

This is interesting - a netboot feature that works over the wireless network.....

As previously confirmed with Apple, the MacBook Air is the first Mac to support wireless network booting (netboot). This functionality works in conjunction with the "Remote Disc" feature, allowing the MacBook Air to boot from, for instance, Mac OS X Install discs that are inserted in other computers' optical drives. This revolutionary capability was accomplished, firstly, via some major refinements to the system's EFI (Extensible Firmware Interface). Robust wireless support had to be added, especially with regard to using secured WiFi networks.

[From How the MacBook Air's wireless boot feature works - MacFixIt]