I have a Sony a100, it comes with some really clunky software but the one thing I do like in it and would love in XnView is a way to view photos by date as in a calender. So I could see the month of June say and any days that I took photos would be highlighted in red or some other colour to make it stand out, I could then click on that day and see what I took.
Maybe something for MP if not regular XnView
Rob