Thanks, Kirk. No chance of a truncated four-digit version, to create a useful (IMHO!) alternative to frame4? Like I said, apart from providing uniqueness to my file names (which are otherwise based on date/time), I find having a four-digit code in the filename useful as a quick identifier... not totally unique, but unique within the last 10,000 images taken, and certainly helpful to locate a cataloged image in a jiffy with just four digits to type in... could put the full 8 digits in the filename but then things start to get a little out of hand... (and it also starts to eat into valuable space in the 40 character limit for the filename printed on the back of my lab prints).
Mike