Latest Blog Module image resizing

Hello,

I am trying to have it so that the latest blog post image is not resized into a square, but keeps the proportions (in the case of a vertical picture). Because it is resized into a square for the thumbnail, the picture is being cropped rather than re-sized.

Is there a workaround for this?

This is the image/blog post:

http://www.dianehourany.com/ (scroll to middle Latest Post Module)

http://www.dianehourany.com/index.php/dianes-blog/entry/20th-st-in-san-francisco-is-where-the-action-is

Thanks in adavnce