One of the announcements at the Let's Rock presentation last week was the iPhone 2.1 update. Steve Jobs boasted that this update will improve your reception, cut down on dropped calls, and exterminate system bugs.
After spending about 30 minutes updating my firmware, I can tell you that it's a vast improvement! I have all five bars almost everywhere I go in the city, and have noticed faster Internet surfing, faster downloads, and best of all — faster backups to iTunes. Have you updated your iPhone yet?