Okay, so Apple's docs don't cover this and it's driving me nuts. I have a customer who's got a new Coreduo 20" iMac, an extensive home network via Ethernet and a new Airport Express. I'll skip to the chase and tell you what's relevant: Her iMac is the geographic center of the wireless network she's looking for but there's a desire to extend the network along her house in one direction. Theoretically I should be able to tie in the Express via WDS as if her iMac was a base station... Except it refuses to cooperate. Am I missing something?!? Her iMac is plugged into the router directly. Her Express is hooked to her stereo three rooms away weith no Ethernet in sight and successfully works with Airtunes but refuses to see her iMac as an "existing network" to join a la WDS. THe idea is to "unwire" her two iBooks and have the express extend the wireless range to the front of the house.