Notifications are a big deal in iOS 5. Taking some cues from Android, iOS has finally unified the notification system and made it less clumsy and intrusive.

Message now appear at the top of the screen (though you can choose to allow them to display in the middle) while you are using the phone and they don't interrupt what you are already doing.

On the lock screen, notifications are displayed in the middle of the screen. These messages can build up over time, for easy access to various message.

The notification bar is accessible by pulling down the top of the phone. By default, your weather widget and stock ticker populate the space, along with any recent notifications.

The weather and stock ticker take information from those built-in apps on the phone. You can choose to turn this feature on or off. Weather is especially nice for finding out current conditions and getting a 5-day forecast.

In landscape mode, notifications work just as they do in portrait. You can choose what apps are allowed to use the notification area on an app by app basis in Settings.

You can choose how to display notifications within each app's section in Settings under Notifications.

You can also choose how many recent items to display. As you can see, if you get a text message while taking a screenshot or browsing settings, it now alerts you at the top of the screen.

Facebook isn't built-into iOS 5 but the new app has lots of options for customizing how you are notified about events, messages or follows.

A full notifications screen.

The Weather and Stock widgets can be turned on and off.

You can choose to associate an AppleID email address with iMessage. If you want to use a different email but don't want to create a new AppleID, you can add the email at Apple.com.

You can now set your email or your cell phone number as the Caller ID settings within iMessage.

The "send" button in iMessage is blue. It's now green when sending a regular SMS.

The "send" button in iMessage is blue. It's now green when sending a regular SMS.

Attaching a photo to iMessage works just like it does in the SMS app. You can also directly send a photo to another person from the Photo app or after taking a picture with the camera.

Twitter now has its own place in the Settings screen. From here, you can install the app and update your account information.

Twitter can now better integrate itself with your Address Book. Twitter can scan the name, email addresses and phone numbers you have on file and compare them with what users have used with Twitter.

If it finds a match, avatar photos and Twitter handles are updated within the Address Book.

You can add multiple Twitter accounts to your device and specify what account is default. You can also adjust notifications on an account-by-account basis.

You can send tweets from the main application or from Safari, Photos, Maps and YouTube.

Double tapping on the home screen button will launch display both the music player and the new camera button.

Tap on the camera button to take a photo without unlocking your phone.

The Photos app might look the same but it has some great new editing tools.

Tapping on "Edit" now brings up a new wave of options that include Auto-Enhance, Red Eye, Crop and Rotate.

Auto-Enhance is supposed to auto-adjust a photo for better lighting and brightness. In our tests, the results were minimal to non-existent.

Cropping a photo is as simple as moving your fingers around the area you want to focus in on.

You can also constrain your crop to a certain size or orientation.

Cropping a photo is as simple as moving your fingers around the area you want to focus in on.

You can also constrain your crop to a certain size or orientation.

After making adjustments, your saved photo is available in your Camera Roll. The changes are NOT destructive, meaning you can go back later and change or remove a crop or adjustment.

Image rotation is a tap. Literally.

You can now send a photo to Twitter or to iMessage

You can add your location to a photo. Twitter will also search your contact list for someone's Twitter username.

You can add your location to a photo. Twitter will also search your contact list for someone's Twitter username.

Reminders is a new core iOS app. It makes creating to-do lists and reminders a snap. Like Notes and Calendar entries, it can be synced with iCloud/

Completed items in Reminders.

I cannot complete anything.

Tap an item to check it off as "complete"

View reminders by date. You can also set a due date and a location update to a reminder.

Safari for iOS 5 got a big overhaul on the backend. It looks the same for users, however.

The nifty Readability-esque feature from Safari 5 for Mac and Windows is now in Mobile Safari.

The Reader mode strips away the default styling and makes reading articles much more palatable and distraction free.

We won't call the Reading List an Instapaper-killer, but it is a similar idea.

You can add articles to a running "Reading List" that is accessible across devices. You can even sync your ist with Safari for Mac or Windows using iCloud.

The Reading List makes it easy to access articles saved for reading earlier in your browsing section.

Mobile Safari now lets users browse the web in a private browsing mode. This means that traces of your activity are not stored on the device.

The chrome around Mobile Safari is black when Private Browsing Mode is enabled.

Links or pages can be tweeted from the "Send to" menu.

You can now share a Map location with someone using Twitter or iMessage.

You can now share a Map location with someone using Twitter or iMessage.

In iMessage, the location comes up as something that is accessible by the other user in the Maps app on their iOS device.

Locations can also be sent via Twitter or direct message.