Running the new iPhone OS on an old iPhone 3G

June 22, 2010 10:43 AM EDT

Users of older iPhones and iPod touches don't get the best features of iOS 4, the new iPhone operating system. But we do get a few new goodies.

The big new feature of iOS 4 is multitasking -- the ability to run selected applications in the background while doing other things in the foreground.

But don't get too excited, my fellow iPhone 3G users. We don't get multitasking. The processor in the 3G just isn't powerful enough. Same thing for the iPod touch G2, which is pretty much the same device as the iPhone 3G, without the phone parts.

However, users of the iPhone 3G and iPod touch G2 aren't entirely abandoned. We do get a few of the good new features in iOS 4.

The biggest new feature for us: Icon folders, to help tidy up your home screens. If you have dozens of apps for your iPhone, it can be hard to find a specific one. Icon folders make it easier. Just press an icon and hold it until all the icons on the screen start to wiggle, then drag one icon onto another. When you lift your finger, the two icons will have merged into a single, black square the size of one of the original icons, with the two icons in miniature inside. It looks like this:

iPhone iOS 4 folders. 

Tap one of the folders, and it expands like this, giving you access to all the apps inside.

iPhone iOS 4 folders - open. 

The second major feature of iOS 4 that's relevant to the iPhone 3G is a universal inbox for the Mail app. Instead of having separate inboxes for each of your e-mail accounts, you can view all your e-mail for all accounts in a single inbox. And messages are threaded into separate conversations.

Mail users can also connect to multiple ActiveSync accounts. That means you can sync to your Microsoft Exchange server at work and your Gmail server for personal mail. Nice!

Other iOS 4 features available to iPhone 3G users: Spell-check, character counts in composing text messages, the ability to show and hide individual calendars, and organizing photos by Events, Faces, and Places (but you have to set that up on iPhoto 09 on your desktop),

Other iOS 4 features not available to iPhone 3G users: Bluetooth keyboard support, custom wallpapers, FaceTime video calling.

Here's a rundown of iOS update compatibility, for all iOS devices:

- The original iPhone and iPod touch G1 (2007) don't get the update at all -- they're not compatible.

- The iPhone 3G and iPod touch G2 (2008) get the update, but don't get multitasking, custom wallpaper, and Bluetooth keyboard support.

- The iPhone 3GS and iPod touch G3 (2009) get all the features except those requiring iPhone 4 hardware, mainly FaceTime video chat.

- The iPhone 4, which ships in a few days, gets all the new features of course.

- The iPad gets the update in the fall.

I upgraded my trusty iPhone 3G to the new iOS as soon as it became available yesterday. I was one of the people who experienced problems. The process took a long time, three hours. I just let it run during that time, and busied myself with other things. Like, y'know, work.

I've tried out most of my major applications, and they all work fine, except one: Push Gmail, a $1.99 Gmail client, which now crashes as soon as I try to open an e-mail message. No big deal, I've just gone back to using the iPhone's Mail app.

As for performance: There doesn't seem to be any net change over iOS 3.x. My faithful iPhone 3G doesn't seem to run any faster under iOS 4, but it doesn't seem to run any slower either.

All in all, the iOS upgrade is no big deal for iPhone 3G users. But it does add a couple of nice features to my trusty iPhone 3G.

I'm looking forward to getting the iPhone 4; it's due to be delivered in about two weeks.

By the way, I've noticed when I start referring to devices as "trusty" and "faithful," it means the thing has become old and decrepit and I'm about to replace it, sticking the old device in the back of a closet for eventual recycling.

Don't tell my iPhone 3G about my plans, though. I haven't told it it's being replaced. I've told it that I'm going to send it to live on a farm where it can play with all the other phones all day.

Update, 7/29: "Apple investigating iPhone 3G software complaints: Users of old iPhone 3Gs are complaining about slowness and bugginess on their phones after upgrading to the latest operating system version. Now, Apple is looking into the problem."

Mitch Wagner Follow me on TwitterVisit my LinkedIn pageFriend me on Facebook is a freelance technology journalist and social media strategist.