After looking at some pictures of the *ist-D on "DPReview" I rather think it is for allowing the camera to communicate with ones computer when it is necessary to upload images.
On the majority of digital cameras there is a 'play' mode and one has to switch the camera into that mode before it will communicate with the computer in order upload image files. Possibly pressing this button on the Pentax serves the same purpose. Just a guess. :-) Harry -- Harold Owen <[EMAIL PROTECTED]>
