Updating operating system iphone 3gs
You cannot do this without hacks, plus it would probably slow your phone down to the point that you must wait forty seconds just to slide to unlock.
You are better off just settling and updating to i OS 4.
i OS 6 doesn't make the i Phone 3GS any slower or more difficult to use than it was before, which should be good news to anyone who keeps theirs around as a secondary or backup phone—indeed, it's pleasantly surprising how many of the refinements and improvements make their way down to Apple's oldest-supported piece of i OS hardware.
This can cause two problems: the first is that owners of not-so-old devices can be left with old software, as is happening to owners of the original i Pad (which was, believe it or not, still the newest i Pad available just 18 months ago).Features from older i OS versions that didn't make it to the 3GS are still not present in i OS 6: these include location-based Reminders (i Phone 4 and newer), Wi Fi Personal Hotspot (i Phone 4 and newer), Face Time (i Phone 4 and newer), Air Play Mirroring (4S and newer) and Siri (i Phone 4S and newer).These missing features generally don't change the operation of the phone—they're simply not present.With the exception of the Siri and Maps sections, just about everything mentioned in our main i OS 6 review applies to the 3GS, including Passbook support, Facebook integration, shared Photo Streams, revamped sharing menus, Do Not Disturb, i Cloud Tabs in Safari, the new Find My i Phone tweaks, the Camera app's exposure lock, the new Mail features, and the new call features, among others.
The new features also don't slow the phone down appreciably.
You don't have much to lose if you upgrade a 3GS to i OS 6, but there's a lot more to gain by investing in a newer device. The CPU is better in the i Pad, but the device has the same amount of RAM (a mere 256MB).