I learned to love my iPhone again after jailbreaking it and installing a few of my favorite apps.  Jailbreaking is worth doing solely for two apps: BiteSMS and IntelliScreenX.  These are both paid apps (via the Cydia store) but well worth it.  BiteSMS allows you to reply to texts from the unlock screen (among other awesome features) and IntelliScreenX shows your calendar, weather, Mail, texts, etc on the lock screen.

If you’ve considered jailbreaking your iPhone, do it.  These links will get you started.  Lifehacker’s article, Best Jailbreak apps, hackers site where the jailbreak is available.