Apple has released iOS 4.3.2 for the iPhone 4 and iOS 4.2.7 for the Verizon iPhone 4. This upgrade fixes various bugs, document viewer, DNS issues, FaceTime issues and battery life problems.
Download the IPSW from the links given below:
iPod Touch IPSWs:
To perform the upgrade, connect your iPhone to your computer and fire up iTunes. You should get a message prompt to perform the upgrade. To force the update, hold down the shift key (cmd key in Mac) and click on βRestoreβ button to open a file dialog box. Point it to the IPSW you downloaded to perform the upgrade.