The Canon PowerShot SD40, also called the IXUS i7 Zoom in Europe, is in a batch of fresh Digital Elph cameras that include the new and improved Digic III image processor. The new ultra-compact camera has 7-megapixel resolution and now includes trendy face recognition technology, courtesy of that Digic III processor. The small size of this $350 camera means some compromises have been made: The zoom is a 2.4x model, and the screen is only 1.8 inches. So do these compromises make the SD40 a party animal or a gatecrasher? Read on to find out.