My idea is to improve the screenshots in the wordpress.org plugin repository. The detail in many screenshots is hard to see because the screenshots are not displayed at full size; they're reduced.
Today, if you right-click on an image and open the image URL, you can view the full size image.
My idea is to implement a click-to-enlarge or lightbox feature for these screenshots. At a minimum, the screenshots could link to their full size versions. Having a lightbox would be great too.