iOS 5 is now available for download -- you might even be attempting to download it right now. Here's what you can expect from the new update.
Notification Center -- probably the biggest change. Notifications no longer interrupt gameplay or video playback -- instead they appear as discreet notifications at the top of the screen and are collated into the new Notification Center where you can interact with them.
iMessage -- free iDevice-to-iDevice messaging without needing to use your carrier's text message allowance or a third party IM app.
Newsstand -- Magazine and newspaper app subscriptions are now available from your device, with notifications to tell you when new issues are released.
Reminders -- Your very own quest log.
Single Twitter sign on -- Twitter is integrated into the OS, so apps that support it no longer need specific signons. You can also tweet directly from the Safari, Photos, Camera, YouTube and Maps built in apps. The Contacts app also supports Twitter IDs now.
Camera upgrades -- Access the Camera from the lock screen with a special button, use the volume up button as a physical shutter release button and use the new grid lines feature to help compose your pictures. You can use iCloud to sync photos between all your iDevices.
Photos -- Basic photo editing can now be performed on your phone -- crop, rotate, enhance and remove red-eye -- and finally, organize photos into albums on your device.
Safari updates -- The iOS web browser now features a Reader option to strip out the crap that clutters most web pages. On iPad, you get tabbed browsing.
PC Free Updates -- a biggie. iOS 5 will be the last OS upgrade you need to connect your phone to a PC or Mac for.
Wi-Fi Sync -- Alongside wireless updates, you can also sync your iTunes content wirelessly whenever you connect to power.
Mail updates -- Now you can format messages, flag them and add and remove folders. iCloud also includes a free email account.
Calendar updates -- Various tweaks including the ability to drag to adjust the time and duration and modify calendars on your device, and share with iCloud.
Game Center -- Updates include profile pictures, public Achievement scores and friend recommendations.
AirPlay Mirroring -- Certain apps will be able to wirelessly stream 720p video to HDTVs via Apple's Apple TV device. The iPad 2 and iPhone 4S are powerful enough to act as a host for split-screen gaming.
Apple says the update may take an hour or more to complete, so make sure you're not going anywhere for a while. It's available now from iTunes -- you may need to click "Check for Update" a few times to make it work, however. Good luck, and see you on the other side!