I have a 2nd gen Extreme base (non dual band). I currently have it running in 2.4ghz mode because of my iPhone. A friend has offered to give me an Express that he was using to extend his network. My thought was that maybe I could set the AEBS to broadcast in 5ghz, then use the AE to extend it running in 2.4ghz mode. That way, my computers could take advantage of the faster connection by connecting to the AEBS, and my iphone could connect to the AE. Couldn't find anything on the net about anyone using this configuration, which leads me to believe that it probably isn't possible....but I figured I'd ask here before I gave up on the idea completely.