[iVenom]

If the antennas on the outside why make the back out of breakable glass? If it had an internal antenna the i could see the point but its not.

[cjvitek]

Aesthetics.

Pure and simple.

Chris

[iVenom]

I know... but i would take some cheap black plastic

[Jellotime91]

The black is much less likely to scratch, it feels much nicer, looks a hell of a lot better.

[cjvitek]

You know what would be cool - a clear iPhone, similar to the clear plastic sides on computers.

[jerrydavid]

The back glass enables the iPhone look better...

[markhunsaker]

I think a solid aluminum would have looked nice lime the first iPhone, although with no black plastic since the antenna is on the outside.

[TLD1]

Although the "glass sandwich" looks nifty and all... I would have preferred some kind of textured material to aid in "grippiness" and so as not to be so fragile. But, that's just me...

[Smlk]

I think the black glass and it being flat looks sharp!

[iVenom]

yes it feels good to the touch. more solid

[Garz]

Much less finger prints. Touch a black 3GS on the back and see how bad the phone looks from fingerprints.

[mpaquette]

Because it looks sweet? After several BlackBerry's and an Eris, I'm so happy to have a phone that doesn't look like a Cracker Jack toy.

[Ipheuria]

I love the glass back and front mmm but now it makes me exciting to think what the next phone will look like? I loved the first iPhone, the 3G was sweet but the 3Gs wasn't that impressive which is why I never got one.

[ddot196]

I love it. I'm sure the next phone will be near identical with perhaps an updated metal band design.

[iVenom]

ditto to that

[KevvyMcD]

asthetics + more scratch resisant = BETTERNESSSSS

[BuddhistGirafe]

Well see. The iGlass on the back makes the iPhone look much nicer. Also, if you ever get into an iFight, you can break off your iGlass, with iMuscles, and break it and iShank someone. Steve thought this through.

[chobbs1]

The glass is nice. Loved the first Phone design hated the plastic on the 3G . Wich is why I waited for the 3GS. And now I love the design again with the glass.

[Duvi]

Aesthetics. Also, there should be less fingerprints, scratches, and
should hopefully put an end to the cracks that the 3G and 3GS
would get even when in a case.

[Kannon#AC]

Since it's so easy to remove the back cover, I can't wait until people start making replaceable backs in different styles.

[ghostface147]

I removed the cover just to see inside. I noticed a little metal clip that touches the back cover snapped open when I removed the cover. I am wondering if that's some kind of alert system telling the software that the phone has been opened, therefore voiding warranty.

However I can't find the piece in the ifixit teardown. I want to look again, but am wary now.

[NavyAV8R]

looks and feels good

[clarkkent]

It's the same class as the front glass, really difficult to scratch

[Raul Lugo]

I removed the cover just to see inside. I noticed a little metal clip that touches the back cover snapped open when I removed the cover. I am wondering if that's some kind of alert system telling the software that the phone has been opened, therefore voiding warranty.

However I can't find the piece in the ifixit teardown. I want to look again, but am wary now.

Thats interesting, let us know if you find something.

[MODiFiEDZ]

Easy repair. I no longer have to worry about sitting on it or using a case. I do use the invisible shield though. I see myself one day taking it off and not worrying about the backside scratching because it's so easy to replace.
So for Apple, it's easy repair, compared to the old not so easy to take apart and put back together 3GS. Plus they used it because they knew that's what people wanted and that they would sell like crazy. I just wish they had steel around the edges of the front and back screen, because that's the only plastic left on the iPhone 4, except the home button I think.