Sony didn't so much enter the market for small and thin digital still cameras as break down the door today when it unveiled a camera that is about the size of a pack of playing cards.

Sony claims its camera to be the smallest five-megapixel model currently available. Small format cameras are also appearing from Casio, Konica, and Pentax.

Sony's new DSC-T1 camera is tall and thin and hosts a 2.5-inch LCD monitor on its rear.

It carries a Carl Zeiss lens with a 3x optical zoom – but the lens doesn't protrude from the camera as a zoom lens normally would. That's because the lens is mounted sideways and is already extended inside the body of the camera, with a prism used to reflect light so that the lens can see ahead. This configuration is gaining favour among designers of small cameras because it helps keep the cameras thin and cuts down on both start-up time and noise.

The maximum resolution available from the camera is 2,592-x-1,944 pixels and there are four additional resolution settings. It can also record MPEG-1 format video and audio at 640-x-480 pixel (VGA) resolution at 30 frames per second. Other features include a USB 2.0 interface and support for MemoryStick Duo and MemoryStick Pro Duo memory cards.

The camera measures 91-x-60-x-21mm and weighs 180g with a memory card and battery inserted.

The DSC-T1 will be available in Japan from November 21, and will be available in the US in January for around $550. UK details have not yet been disclosed.

Sony also announced a new member of its Cybershot U series yesterday, the DSC-U40. This looks similar to the currently available DSC-U10 with the same sliding door covering the lens on the front of the body, although it is a little more stylish than the earlier model. It has a two-megapixel CCD image sensor, a one-inch LCD monitor and uses either MemoryStick Duo or MemoryStick Pro Duo memory cards for storage. This camera also reaches the US in January.