first let me say thanks for making wordpress amazingly fantastic. You all rock.
My request is this: right now wordpress does a great job of resizing images but there is no way to know what the url of the resized images will be. I think when viewing an image in the media library there should be extra urls after 'file url'.
Likewise, when linking an image to a larger version of that image there should be an option to link to various sizes. This is a big issue when relying on WP to resize a big image to reasonable dimensions - but still wanting a thumbnail to link to a larger version. Basically relying on WP more and more for image editing - a great option