The new Flex Slider module for Drupal 7 offers a real easy slideshow. I'm testing it here with just the minimum options. The Views and Views Slideshow options are not enabled. My test is with some images sized to 300px wide and Flex Slider knows to resize itself to fit the available space. It even looks real good on my iPhone.
This has been updated to the 7.x-2.0-rc1 release of Flex Slider.