iPhone 4S and iCloud: Never lose another file?

iPhone 4S's announcement Tuesday offered a refresher and some new details on Apple's iCloud storage-and-sync service. The feature, which will work on iPhone 4S and other Apple devices, will compete with Amazon's cloud storage service.

New iPhone 4S! Updated (and cheaper) iPods! With all the focus on hardware during Apple’s announcement on Tuesday, you might have glossed over the new details about the software that powers it: iOS 5. One of the operating system's most interesting features is iCloud, which arrives on Oct. 12 (two days before the iPhone 4S).

A quick primer on how iCloud works: you might have noticed that iOS devices top out at 64GB of storage space. That’s reasonably capacious, but hardly enough to store a large media collection. That’s because rather than selling devices with huge drives, Apple wants you to store your stuff on their servers (in the “cloud”), and sync it to your iPhone 4S, iPad, iPod Touch, or Mac over the air.

iCloud was first introduced back in June at the Apple Worldwide Developers Conference, so a lot of what we saw today was a recap. But Apple also shared some more details on how the service works.

First, it’s baked right into many of the apps in iOS 5, so the syncing happens automatically. You can download (or redownload) anything you’ve bought on the iTunes store whenever you want, on any iOS device. This includes music, TV shows, pictures, documents, apps, and books, as well as Safari bookmarks, mail, contacts, and calendar data. Movies are the exception here – Apple’s not letting you sync them through iCloud yet.

Apple’s also pushing iCloud as a backup service. When your iPhone, iPad, or iPod touch is plugged into a power source and connected to a Wi-Fi network, Apple will once a day back up everything stored in iCloud across your devices. Everyone gets 5GB of iCloud storage for free, and media purchased through the iTunes store (music, apps, books, and TV shows) as well as photos taken on iOS devices don’t count against that limit – so lots of users probably won’t hit the ceiling. If you need more space, you can get an extra 10GB, 20GB, or 50GB per year for $20, $40, or $100, respectively.

ICloud also powers a couple of nifty new services that we saw demonstrated at Tuesday's iPhone 4S event. iTunes Match, a $25/year service, will let you store your music collection in the cloud and play it on any device with iTunes, regardless of local storage. (The service “matches” songs against the high-quality versions in the iTunes store, and uploads only what it doesn’t recognize – hence the name.) Apple also gave a peek at “Find My Friends,” a nifty service that can share your location temporarily or permanently with friends who are also running iOS. It’s got the potential to be creepy, but Apple’s got it locked down with some pretty tight privacy and parental restrictions, and it could certainly be useful for, say, keeping track of family on the ski slopes.

Apple fans, what do you think about iCloud? Are you looking forward to being able to pull data from the cloud, or are you furiously buying up discontinued 160GB iPod Classics to show your love of local storage? Let us know what you think of all this in the comments.