Best to attempt via Software Update in settings I think rather than iTunes.

iOS 5.1 contains improvements and bug fixes, including:[LIST][*]Photos can be deleted from Photo Stream[*]Camera shortcut now always visible on Lock Screen for iPhone & iPod Touch[*]Camera face detection now highlights all detected faces[*]Redesigned camera app for iPad[*]Genius Mixes and Genius Playlists for iTunes Match subscribers[*]Audio for TV programmes and films on iPad optimised to sound louder & clearer[*]Podcast controls for playback speed and a 30-second rewind for iPad[*]Fixes an issue that occassionally caused audio to drop for outgoing calls[*]Addresses various bugs affecting battery life (saves best until last!)[/LIST]A very large update which takes a long time to install after download. As you can imagine downloads are also very slow at present!

New Lockscreen in iOS 5.1

Can you turn off 3G? Wanna know before I upgrade from Beta 3.

Unfortunately it seems not - Carrier Network Selection screen still has only the one option (i.e. 'Automatic' - On/Off). Turning to Off just brings up the Network List as before

After update to 5.1 new versions of Find My iPhone, Twitter, Garage Band, iBooks are available for download.

I think I might wait, I remember when 5.0 was released what a load of hassle that was

And if you're sensible and remember the complaints and problems from when 5.0 came out, you'll wait a couple of days until the server bashing has died down before you get it.

Upgrading now
Took about 20 minutes to verify the install.

Certainly caning my broadband connection tonight.

2 x iOS 5.1 downloads + 2 x 1GB App Updates.... so far!

I have just updated my iPhone 3GS through the Software update. Took about 20 minutes to download and to verify. Installing at the moment.... So looking good at the moment.

Doing ipad and iphone now..started ipad later and thats already verifying..iphone nearly finished downloading. so far so good.

Yes you can! Go to Settings-General-Network and Enable 3G is at the top of the list!

As soon as an untethered jailbreak arrives, I'll finally go iOS 5.

Doing my 4S just now.

It's never been in that menu, see the above post.

The feature has always been dependent on your network. They have the ability to disable the option (Three does this in the UK).

is this update for the iPod touch as well?

The toggle is indeed back, apart from Three.

On iOS5 on the iPhone 4s, the option to toggle was not there on any network.

Quick and painless upgrade, however it seems nearly all my apps need updating..

Upgraded 2 iPhones, 1 iPod and 1 iPad and all worked great.

Yeah I upgraded mine.

I'm suffering from overloaded servers and can't update through iTunes or OTA Could be here a while....

Updates just released for Find My Friends and Remote.

Strange I had no issues here, took about 30 secs to download for all devices.

Pretty awful that, five months after the 4S was released, the full features of Siri STILL haven't been implemented outside the US.

And it never will by the looks of it....

Apple: We never said Siri would actually work in the UK