[turtle]

When the computer is off or you are off network it just stores the images on the SDHC card like a normal card. Then once in network it begins to download automatically with the camera on.

Transfers only happen when the camera is one, so you know it isn't going to kill the battery in your bag just communicating over the network. I will say that there is a slightly more noticable battery drain with my wife's Canon SX110, though it's more likely because the LCD has to stay on longer so the transfer can happen.

Edit: I didn't realize I never came back to share how much we love this card.

It really is great for our house. My family will be running around the house doing our thing and see a great shot and take it. It's downloaded while we are still running around and there's no fuss. It just works. I can't say the software on my wife's computer has effected it's speed of abilities either. It is a 1st gen MacBook though. If you interupt an image being downloaded by turning off the camera the card picks up later when it can. I have seen it give a card error on powering back up a few times though. Turning the camera off then back on fixes it though.