Can I eject the CompactFlash card while the camera is on?
Usually. The only time you shouldn’t remove the card is when the camera is processing images. If the red “Busy LED” is blinking, leave it alone until the camera finishes. Otherwise, it’s perfectly fine to pull the card with the camera on, and insert it into a running computer. The red “Memory Busy” LED is not the same as the green “Please Wait” LED next to the viewfinder. The memory LED is hidden under the CompactFlash eject button. When this one is blinking, do not eject your memory. It generally continues flashing for a few moments after the green LED stops.