I own six cameras:
1. Canon PowerShot SD800 IS (link)
2. Casio Exilim
3. Sony MiniDV Handycam
4. iPhone (link)
5. Diana+ (link)
6. Macbook Pro iSight (link)
I just got the iPhone and Diana+ this Christmas and have limited experience with both.
The Diana+ uses medium format 120 film. I’ve only shot in color. You can see my first three rolls here. Having to wait for the local camera shop to develop my film highlights how convenient immediate feedback on digital cameras is. And how impatient I am.
The iPhone seems to take great pictures (for a “phone”). There is no flash, so it is a poor substitute for my Canon PowerShot during nighttime outings. Otherwise I’m thrilled with it.
The Canon PowerShot has given me what I expected – portability and above average pictures. The lack of shutter control is frustrating, but otherwise a good compact camera. I also love the video capabilities and recently upgraded to a 4GB SD memory card that allows 33 minutes of video.
The Casio Exilim was my main camera before the Canon PowerShot. It has 4.1 mega-pixels and takes good pictures, but is slow to shoot.
I rarely use the Sony Handycam. I will make a point of shooting more higher quality video with it this year, although it is not HD. That leaves me somewhere in between the Canon video quality and HD.
The MacBook Pro iSight is used almost exclusively for goofy shots and video chatting.