I’ve bought a SanDisk CompactFlash Extreme III card for my Canon EOS 350D. The Extreme III is designed for serious photographers who demand one of the fastest and most durable CompactFlash cards on the market. That’s because only the Extreme III CompactFlash cards feature innovative ESP Technology for the best performance. ESP stands for “Enhanced Super-Parallel Processing”. Simply put, it means you are getting the fastest read/write speeds available – an amazing minimum 20MB per second sequential read and write speed – speed you’ll definitely appreciate whenever you find yourself shooting in AI Servo AF (*) modus and storing pictures in harsh environments, extreme temperatures or at high altitudes.(*) AI Servo AF is an autofocusing system designed exclusively for Canon EOS cameras. It uses a form of Artificial Intelligence (AI) to determine the speed and direction of moving subjects, then focuses the camera lens to a predicted position (Focus Prediction Function) in order to increase the probability of obtaining a sharp photograph.