Emailing "Tip: iPhone - How to Reset Wi-Fi, Cellular Settings"
TUAW's posted a useful tip for iPhoner's who find their cellular-data access sluggish or not working. It recommends users hit the "Reset Network Settings" button, which cleans the slate on the iPhone for Wi-Fi as well as cell phone reception. That button is located here: Settings > General > Reset > Reset Network Settings. I've tried it and it's done the trick on a few occasions. See
here to learn more.