what about this?
what about this enabler? I got it for free (its a shame we have to pay for this) at the Apple store in Argentina, I havent tried it yet since at home I've got a wifi-G but it should do the trick and ITS A LOT CHEAPER!
http://store.apple.com/us/product/D4141ZM/A?mco=36A3C0EC
Overview
Please read this entire page before purchasing and installing this software.
Many Mac computers with an Intel Core 2 Duo and all Mac Pro computers with AirPort Extreme can be enabled to access 802.11n-based wireless networks. If you purchased one of these Macs, you can use the AirPort Extreme 802.11n Enabler software to activate this advanced wireless capability.
Important note: The Enabler is included free with the new AirPort Extreme Base Station with 802.11n. If you purchase a new AirPort Extreme Base Station, you do not need to purchase the Enabler separately.
These Macs have the 802.11n hardware built-in:
* MacBook Pro with Intel Core 2 Duo
* MacBook with Intel Core 2 Duo
* Mac Pro with AirPort Extreme option
* iMac with Intel Core 2 Duo (except the 17-inch, 1.83GHz iMac)
Please make sure you have one of these Mac computers before purchasing the 802.11n Enabler software. It is not compatible with other Mac models.
Do you need the AirPort Extreme 802.11n Enabler?
Before purchasing the 802.11n Enabler software, please check to make sure that your Mac does not already have the 802.11n enabler already installed.
* Open Network Utility (found in the Applications > Utilities folder)
* Under the Info Tab, choose Network Interface (en1)
* In the section "Model: Wireless Network Adapter," if it says (802.11a/b/g/n), you already have the 802.11n enabler installed. If it says (802.11a/b/g), you do not have the 802.11n enabler installed.