Edimax EW-7711UAn Wireless nLITE 3dbi High Gain USB Adaptor

In a nutshell: worked well with older laptops without wireless card built in, found it pointless with newer laptops as performance did not improve, usefull with desktops and clumsy when used with netbooks. Short answer is - do you actually need this product? Long answer is - do your research and you'll find superior products on the market but at a higher premium to pay. I suggest having a look at netgear's products as they seem to be more effective at this job than most other products on the market.

This is a really well priced adapter especially giving an older Apple Mac wireless capability or indeed upgrading beyond older Airport wireless cards to operate with more modern wireless routers with higher WPA/WPA2 encryption.
I use it wlth a 2001 vintage iMac G4 which only has USB 1.1 - but don't expect it to be as fast as with USB 2.0.
The only downside is that there is no accompanying literature to help with the install - it's all on the CD, see 'Driver-Utility for Mac', open the dmg disk image and select your version of Mac OS X.
However if you have 10.4 Tiger, beware the driver on the disk doesn't work and you need to download: USB RT2870 version from http://www.ralinktech.com/ralink/Home/Support/Macintosh.html-

Find USBWirelessUtility in your Applications folder and run it before plugging the adapter into your USB.
Set-up is fairly automatic - just go to 'Site Survey', to select your router, then 'Add Profile', and then enter your WEP/WPA key under 'Authentification & Security'.