Olympus has launched what it claims is the world's smallest 4-megapixel camera - and it's so small it can almost fit entirely behind a credit card. The aluminium camera sports a 2.8x optical zoom and 2.5x digital zoom, says the company, as well as pixel mapping and noise-reduction technology. The new pixel-mapping function automatically calibrates the CCD chip on demand to ensure each of the four million pixels is primed for action, says Olympus. The noise reduction system compares images against a black background to identify then remove all noise from the image. The result says the company is clearer images, especially long-exposure images. Other features include the ability to capture QuickTime movies, USB AutoConnect for quick linking to PCs, and an 'optimized' graphical user interface. It is due to ship in October for both Mac OS and Windows, and will cost around £699.99.