[mattrivett]

If you could do anything to the iPhone 4 to improve it what would it be?

Be creative

[btkm]

Built-in Vuvuzela button. Is that creative enough? Perhaps a button that causes the phone to flash like crazy and make loud noises... I'd call it the "look at me button" - or LAME button for short.

[Frederico]

Still not sure I'm in love with the "sharp" edges. I love the look, just not certain about the feel.

Wish the front facing camera results were not so grainy in most lighting.

Wish I could lock Landscape mode, but I guess that's really on iOS issue, not iPhone 4-specific.

I barely regret signing a two year contract and paying $300 to get this amazing device, as opposed to the $600 cash I paid for my 1st gen with no contract, banking that I could eventually go somewhere other than AT&T. I did it because Murphy's law says the second I sign a contract to save money, there will be a Verizon option for the rest of you.

You're welcome.

[popshed]

My only two bugbears are:
1) The alarm clock should work even when the phone is switched off and should conserve a tiny amount of energy in order to activate the alarm even when the battery has drained completely. My old phone did this and it wasn't unusual in that respect. It also managed to do it seven years ago.

2) Dialog boxes need fixing. When I'm playing Real Racing I don't want to have to switch airplane[sic] mode on to stop those annoying [Network lost {Settings | Dismiss}] dialogs from popping up.

[JohnTheBastard]

Here is the obvious. My current Sprint SERO plan is 500 minutes, unlimited 3G data, unlimited texts, and tethering for $30/month. A plan on any carrier that is even remotely competitive with that would be a good start.

Beyond that, 4G data, wi-fi connection sharing, more flexible support for a wide range of video codecs/resolutions/etc. Adding more high-powered filtering and photo processing features from apps like aperture, lightroom, and photoshop would be great. The HDR capabilities are a good starting point, but a mobile photo processing app as powerful and polished as the mobile iMovie seems like a natural direction to go.

Resolution-independence support so there is less distinction between iPhone and iPad apps would be a good next gen step.

My biggest irritation, though, is probably a lack of convenient access to content. Its a ridiculous pipe dream as far as apple approval goes, but could you imagine the awesomeness of a iOS native Miro-like bit torrent client that subscribes to your favorite shows? Bypass all the limitations networks put on iTunes, Hulu, and so forth about who can have access to which content on which device. Don't worry about taking a laptop on your travels just so you're able to sync content.

[CIA]

Make it a little thicker so it can fit a bigger battery. "The iPhone 4b, 20% thicker, 400% more juice!"

[zacharace]

Similar to the psychotic flashing: a "flashlight key" that turns on constant flash (as in movie mode). Flashlight and blinding utility!

[hamishb]

Multi-user. Swipe right to get Spotlight, swipe again (or maybe two-fingers) to bring up a multi-user login pane.

That way I can have a login for my little daughter - she can play games with Airplane mode on (that way she won't call or SMS my clients).

Log her out when finished and I log back in with my settings returned.