For example, you can now access and interact with notifications, see album cover art and music playback controls, and jump directly to your camera without ever having to go to the home screen.
Another nice touch: When your phone is locked and you receive a call, the lock screen features a new text-and-reject feature that simultaneously declines the call and sends a message to the person explaining why you can't talk. You can pick from a list of generic responses or add your own custom message. (You can permanently edit/change the list of default responses by going into the settings section of the Phone app.)
As with past versions of Android, Ice Cream Sandwich gives you the ability to set a security pattern, password or PIN to protect your phone. It also introduces an intriguing new option: facial recognition for phone unlocking. Once configured, all you do is hold your phone in front of your your face. If all goes well, within a second or two, it recognizes your features and unlocks your device.
I found the facial recognition system to be fairly accurate and incredibly satisfying to use. In my tests, the system was able to recognize me roughly 90% of the time, even when I was wearing eyeglasses or a hat or making some silly face (for testing purposes only, of course). The times when it didn't work were usually when I was in an extreme lighting condition or holding the phone at an unusual angle. But getting your face rejected, while perhaps mildly demoralizing, is not a big deal; you just enter in a backup password or pattern and you're good to go.
Google does note that the facial recognition option is less secure than a pattern, password or PIN; a disclaimer on the phone goes as far as to tell you that "someone who looks similar to you" could potentially unlock your phone with the feature activated. Some users have reported being able to trick the system into unlocking by holding up a photo of the phone's owner; I tried and was not able to replicate that. I also tested the system with my brother, whom people often mistake for me, but the phone wouldn't unlock with his face.
The take-home message: Facial recognition is convenient, novel and impressive -- and in most cases, it's pretty secure. But if you really need to safeguard your data and can't take any chances, it might not be the right choice for you.
Camera and Gallery
Android 4.0 includes a brand spankin' new Camera app that's chock full of surprises. The app's interface boasts some significant improvements, but the added functions are what really steal the show.