This plugin adds an "Insert Image" button to the top right corner of the edit screen which opens an image browser to select from all previously uploaded images and add the appropriate code to the post. If you want, you can consider it a sort of mini-gallery to select the images from.
Current features include atomagical recognization of thumbnails, sorting images by name or by time of last modification for easy selection and many more. Apart from that, the new version now supports displaying images on multiple pages in a gallery-like style, thus you can handle large(r) amounts of images without problems.
You can download the plugin here.