Another thing I'm not keen on is touch-screen interfaces. As I pointed out in my review of the Samsung NV100HD last week, most of them really don't work very well. However as I also pointed out, one of the few cameras to get touch-screens right was the Sony T700, and happily the T900 has exactly the same huge 3.5-inch 921k resolution touch-sensitive screen as that model. This is really the only way camera touch screens can work; a really big screen and a limited number of large well-spaced button areas. The T900's touch interface is extremely well designed, and as a result it is quick and easy to use, making it one of the few touch screens that actually enhances the experience of using the camera. It also responds to a stylus, so even if your fingers are even larger than mine you'll still have no problem.
The other key feature is HD video recording with stereo sound from twin built-in microphones. I was initially confused by this, and I suspect I won't be alone, because on the box it has a prominent bright yellow logo proclaiming "Full HD 1080", and I thought I'd discovered the reason for the camera's high price. Full 1440 x 1080 HD video would indeed be a unique feature on an ultra-compact camera, however in much smaller letters beneath this logo it says "Still image", and sure enough the camera can playback still images to a HD TV via an HDMI cable at 1440 x 1080 HD resolution. In video recording mode it is limited to 1280 x 720 resolution at 30fps.
The T900 has a wide range of other useful features, including touch-screen focus point selection, an enhanced face detection system with adult or child priority, face motion detection and an adjustable smile shutter trigger, automatic red-eye correction, intelligent scene recognition and D-Range Optimiser with two strength settings. All of these work smoothly, although the DRO is not massively effective. The T900 also has optical image stabilisation, which works well, allowing full-zoom hand-held shots at shutter speeds of around 1/15th of a second.
There are a number of features in playback mode too, some of which use the touch screen interface for retouching or adding effects to pictures. Some of these are novelties such as radial blur or starburst filter, but others are more useful, including sharpening and red-eye correction. One however is truly ghastly; the Happy Faces setting warps your victim's face to make it look like they're smiling. The effect is quite disturbing.