Chatting on an iPhone 4? Avoid covering both sides of the lower left corners' black strip to guard against dropped calls.
Font to small on the iPhone 4? Tap settings, general, and accessibility. Then select large text to change the size in contacts, mail, messages and notes.
Writing texts from your iPhone 4? Go to the settings menu's messages tab and turn on character count to see how many characters you use.
iPhone battery dying fast? Lower the brightness to its minimum level to help it last longer.
Searching the web on the iPhone 4? Swipe right from the home screen to reach the Spotlight screen. Then type in a query and scroll to the bottom of the results list to look it up on the web or Wikipedia. A-ha.