Has Camera Bits ever given the idea of a stripped-down version of PM, a kind of "PM Lite", any thought? I have many friends who when they see me using PM are very impressed by it's speed and simplicity, but with all the extra power in PM it is overkill for their needs and way too expensive. (I'm talking here about amateur photographers, and not even serious amateurs, just happy snappers really.) I know very few people who like iPhoto, most people in my experience preferring to manage their own folders and archive of holiday snaps, but want a efficient and fast way of making selects and viewing a folder of images in Preview mode in PM or in a slideshow. If you stripped out all the more advanced stuff, and just left in simple tagging, viewing, renaming and copying / saving you would have a very nice little app that might expand the market for PM.
Obviously this is not something I'd need personally, but based on my experience I think there could be a market for it. There are already similar apps of course, but none have the speed or simplicity of PM, and I try all I come across looking for something to recommend to non-photographer friends who won't pay $160 for something that is way more capable than they need. A Lite version of PM at a lower price would be a whole extra market for you.
