Here's a quick tip for people who are upgrading their iPhone: when you restore from backup it doesn't restore your Keychain so you need to re-enter all of your passwords.
You may say "Well, duh Tim! Everyone figures that out fairly quickly!" And yes, you probably put your email and your WiFi passwords back in fairly quickly. If you use MobileMe though, it might not occur to you to go re-enter that password. If you don't then the the iPhone just silently stops syncing. Eventually this will cause you a problem if you think that entering appointments on your phone puts them on your main calendars.
Once you get into the proper screen you'll see that the Password field says "Required" instead of a series of dots, but Calendar or Contacts will NEVER say "Hey, you know we haven't been able to sync for the last week."
You may say "Well, duh Tim! Everyone figures that out fairly quickly!" And yes, you probably put your email and your WiFi passwords back in fairly quickly. If you use MobileMe though, it might not occur to you to go re-enter that password. If you don't then the the iPhone just silently stops syncing. Eventually this will cause you a problem if you think that entering appointments on your phone puts them on your main calendars.
Once you get into the proper screen you'll see that the Password field says "Required" instead of a series of dots, but Calendar or Contacts will NEVER say "Hey, you know we haven't been able to sync for the last week."