Today was iPhone 4 day! Yesterday for some very lucky folks. Yes it is a great phone, and a big upgrade compared to my old 3G. So there were a few upgrades for me that other people have already experienced with 3GS like the compass and voice control. Finally multitasking, I knew what I was giving up when switched from Palm Treo all those years ago, but I did miss listening to the radio or Pandora in the background while I checked my email or surfed the web.
The display is truly crisp. You can see the difference with the images and text. I plan on testing some of my apps to see if upgrading the images is worth while. I was so impressed with the 3G display, but now that I have used the Retina Display the 3G is not so great anymore. It is amazing how quickly we become used to superior quality.
The phone is nice and fast, so responsive, I used my 3G quite a bit for small tasks and think that the new found speed is going to result in me using the iPhone 4 even more.
Having multitasking again is great. If I remember correctly on the Treo you had to hold down a button to get back the home screen if you wanted to keep an app in the background. I seem to remember that I had to consciously make the decision. On the iPhone 4 all the apps are put into the background automatically, which I don’t really like as I now have to consciously remove them. Maybe I will forget what is running in the background and let the system handle it.
Facetime is great, I tried it and it worked well so long as you do not pan too quickly. Being able to switch between the front and back facing cameras is a fantastic addition, especially when you are trying to take a picture of yourself and friends. The flash is a another nice addition. I noticed that you can make the flash stay on when you do a video shoot. No doubt someone will make a better flashlight app.
I had been reading that people had been having problems with the signal strength based on the way you hold the phone. I am a lefty and this has not been and issue for me, my hands are usually quite dry so that could be a possible reason.
I took a couple of shots with the camera. It works pretty well, but I find that images can easily become over exposed 
as can be seen in the photo I took with the rear facing camera.
I found the video quality to be great, and being able to record in HD is a big plus. But also noticed the same washed out issue with the video as you can see in this short clip I took. BonePony at Rhythm on the Rails. I need to try the camera under different lighting conditions. In general the colors seem to be enhanced to give a livelier image quality.
The one extra software feature that you can purchase is iMovie which you can download from the iTunes store. iMovie will only run the iPhone 4. This is very much reduced version of iMovie on the Mac, but you can make some cool little presentations. I need to play around with that some more.
Time to play some more.