Whats the quickest way to crop pics?

What is the quickest tool that can let me choose a rectangle (of a predefined size) within any picture file, and it should crop it to that. Something like the tool you get when uploading a Gravatar ... remember?

Typical image editing software like Paint.NET or Photoshop is too slow, you have to open the image file, select a rectangle manually, crop, save, close ....

Solution 1:

There is JPEGCrop, which is a Windows GUI application for most of the jpegtran features:

A new -crop option has been added to jpegtran for 'lossless' cropping of JPEG images:

    -crop WxH+X+Y  Crop to a rectangular subarea

Solution 2:

ImageMagick has crop options.