One of my favourite sim destinations is the Faroe Islands. Ryan Andersen and Peter Poulsen have given us a very nice freeware scenery, and Jens B Kristensen's DC-4 is not pressurised, so I have an excuse for staying low enough to enjoy the view.
I have been experimenting with sizes to find a good compromise. I use YAFFS, and Irfan View to resize the shots. This is 1024 wide, resized and sharpened from 1296. At 72 DPI it comes in at just over 400KB.