Apple’s latest mobile operating system, iOS 5, is becoming a great success. People love it for its notifications and over the air updates. Unfortunately, a lot of people haven’t upgraded yet. I know many friends with iPhones and other Apple products who still run iOS 4. I don’t know why you wouldn’t want to upgrade to iOS 5; it’s an amazing mobile OS that incorporates the best that Apple has to offer.

iOS 5 includes integration with iCloud to keep all of your purchased music in the cloud and a notification center that gives you everything you need to know about what’s happening inside of your iDevice. I really like that the device is self-contained. iOS 5 cuts the cord with the computer; you can download music and update the device over the air without the need for plugging it into iTunes for the nearly one gigabyte file once required. Now, with iOS 5, those updates are only a couple of megabytes in size and take a lot less time to update.

I’ve compiled a list of the top ten reasons that you should finally upgrade to iOS 5 and how it’ll make your experience better. If you or a friend haven’t upgraded yet, be sure to pass on the following list to them.

Notification Center is possibly the biggest feature of iOS 5. It’s an all-in-one center for seeing all of the notifications that come from your applications. Notification Center is also one of those features that Apple users have been asking for since the beginning of time. Android uses complain because they say it’s a rip off of Android’s pull down notifications, but the implementation is purely Apple’s doing.

iMessage brings not only iPhone users closer, but also iPod touch users closer. iMessage brings free Wi-Fi messaging to users of both iPhones and iPod touches. You can send messages to individuals or groups from an iPod touch, iPhone, or iPad. iMessage is for those users on a budget and who don’t have unlimited messaging plans. Giving users the option to message others for free over Wi-Fi is ingenious. It has definitely caught the eye of many users.

Twitter integration is another amazing thing that iOS 5 offers. Everything in the base iOS 5 system is integrated with Twitter. It’s interesting how Apple associated itself with Twitter over Facebook, but it’s a great integration. Easily tweet from inside the Photo app, and it can instantly send pictures and videos to Twitter without going into the official Twitter app to do anything. The base Twitter app is very powerful and offers great innovation inside the iOS 5 system. I’m still waiting for Twitter to integrate with Siri.

Edit photos inside the Photo app. Simple photo editing has been brought to iOS 5 to touch up those amazing pictures slightly to bring out their true beauty. Instead of importing photos into your computer or using another app within the device, the default Photo app has simple photo editing functions to make your photos pop. Crop, rotate, and remove red-eye are some of the amazing features within the application.

Newsstand is great for the daily readers out there. Applications such as The New York Times and Popular Mechanics, just to name a few, integrate with Newsstand to bring you the latest stories and issues with one click. The Newsstand application is a drawer that is laid out just like a newsstand where you can see the front page of the always current magazine and look inside of it. You can subscribe to these periodical applications and, whenever there are updated versions, they’ll download into the background and be ready for you when you’re ready to read them.

iCloud was another strongly anticipated application that has rocketed the movement to iOS 5. iCloud brings all of your songs and applications into the cloud and allows you to download them anywhere where your iCloud account is attached. It was also a hassle before to get your music and applications back after you reformatted your iDevice; now, being able to one-touch download your music back from iTunes is amazing. Alternatively, if you buy a song from iTunes or an application, iCloud will automatically download it to your device when you’re ready to use it. Right now, iCloud is a closed circle for only Apple made products, but it’d be great to let third-party users use it (such as Dropbox).

iTunes Match was a little late to the gate when releasing, but it’s soon to be a hit. This yearly subscription based service takes all of your music and matches it to Apple’s database, instantly making it available to you on any device without having to plug it in to sync. If it can’t match it, it’ll upload your music to the cloud for a low yearly fee. Also, if your source audio is of low quality, it’ll make the higher quality version available to you for downloading and listening, which is pretty hot.

Better camera availability is tied in strongly into the applications. It’s now easier than ever to pull up the camera app from the lock screen by double tapping the home button and clicking the camera icon. With that, Apple has also enabled the volume buttons to act as the shutter release for the camera to easily take pictures in landscape mode.

iTunes Wi-Fi Sync allows for syncing with your library over the air. This is, again, a part of Apple’s initiative to cut the cord and make its devices self-sufficient. Your iTunes library is a precious space because of all the music that you’ve probably accumulated over the years. I know that if I lost my iTunes library it would take me months to get back the gigabytes of data that I have. Some of those songs I’ve ripped from old vinyl records. So with iTunes Match and Wi-Fi syncing, I have them on my devices and in the cloud. This also enables you to download iTunes-purchased apps automatically to your device.

If you or a friend hasn’t done so yet, take this list as encouragement to finally update your device to iOS 5. There are so many wonderful and cool features in iOS 5 that we couldn’t possibly fit them on one page. If you have anything else to persuade iOS 4 users to switch, leave them in the comments below.