From Two Pilots:
Image Resize Guide allows you to make context-sensitive changes to the image size and aspect ratio by removing "unnecessary" portions yet keeping the "important" features intact. Removes objects from photos without visible traces. The best results are achieved against the background of snow, water, or greenery. Important areas can be specially marked and includes stepwise animated demo samples.
What's new in this version:
In version 1.4.1 area Selection can be changed by right-clicking.