I spent literally an hour trying to get my new iPhone purchased 7/31/09 to join the wireless network at home. I finally reset the router with the reset button on back and set Wireless Security to the following:
WEP
Encryption: 40/64 Bit
Created a Pass Phrase
Generated the Key.
I entered the generated key in my iPhone when asked for it worked the first time.
Evidently iPhones do not like WEP 128 bit encryption which is the setting I had before.
Hope this helps someone to avoid the frustration I experienced.
Paul
http://www.hairdohairstyles.com