Symptoms:
Starting a week or so ago, after over a year of problem free operation...
Wireless networks connect, yet no data is delivered via wireless.
-Pages cannot be browsed
-Emails never send or receive
-Activity indicator churns but nothing goes in or out over wireless.
-Connecting to wireless can be instant or take 2 minutes
-Other wireless devices connect and work fine on my wireless network
-My phone works fine on other wireless networks
-When connecting to home wireless it connects and the phone switches to the correct IP address, etc.
Things I tried that did NOT work:
-Reboot phone
-Reboot wireless access point
-Reboot wireless access point and gateway/route at same time
-"Forget network"
-Change security wep/wap/wap2/etc
-Reset network settings on phone (while rebooting all network equipment)
-Change wireless to another channel
-Change wireless name
-Forcing an IP lease renewal on the phone.
What finally DID FIX it:
-In my wireless access point, I reserved the IP the phone had been using for another device.
-Renew the lease on the phone (Settings>wi-fi>blue arrow by wireless name>Renew Lease button at bottom
-Phone switched to a new IP address
-Everything works now.
I hope this helps some of the folks struggling with this.
Best of luck all.