First off: The aria extreme is Cardbus (32 bit PCMCIA). There is no way to get this to work on your ibook (as far as I know). Yes, it may look like the internal airport card. No, it isn't the same connector in reality.
In fact, I am not aware of any means to get 2 radios into an ibook (running panther). As I recall, the D-Link USB adapter that's "Made for Mac" doesn't work in 10.3.
I have, in fact, used multiple radios on the same machine. MacOS X handles everything. When one interface goes down, or becomes unavailable, the next one receives the traffic. However, you must realize that since you will be on different networks, your IP address will obviously be different, and that because of this, the transition can't be "seamless," because all sessions to radio 1 will be lost, and radio 2 with a different IP will have to recreate them all.
Xplain's use of MacNews, AppleCentral and AppleExpo are not affiliated with Apple, Inc. MacTech is a registered trademark of Xplain Corporation. AppleCentral, MacNews, Xplain, "The journal of Apple technology", Apple Expo, Explain It, MacDev, MacDev-1, THINK Reference, NetProfessional, MacTech Central, MacTech Domains, MacForge, and the MacTutorMan are trademarks or service marks of Xplain Corp. Sprocket is a registered trademark of eSprocket Corp. Other trademarks and copyrights appearing in this printing or software remain the property of their respective holders.
All contents are Copyright 1984-2010 by Xplain Corporation. All rights reserved. Theme designed by Icreon.