iOS 6 is out and about if you have and iPhone 3GS, iPhone 4, iPhone 4S, iPad 2, iPad 3, and iPod Touch 4th gen, you can run iOS 6 — at least some of it. For example, if you have the iPad 3 — you will get Siri. If you have the iPad 2 — you won't.
To update, you can either connect to iTunes and update that way, or use the built-in Software update. If you don't want to wait to get prompted, you can simply go to Settings - > General -> Software Update.
Note: you will need to have enough room on your device to update. I had less than 2.1 GB left on my iPad, so I was unable to download and install it. You can get around this caveat if you update from iTunes. I chose to delete some items to free up enough space that it was requesting (it needed 2.7GB on my iPad).
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