WordPress Plugin: WImage Browser
First, you can find the â€œAdd All Coder & Closeâ€ link in the bottom-left corner of the browser window. Press it, and all the codes for all the images will be added to the post, and then the . This option is great if you want to mass-add all images in the directory (unless you want to click â€œGet the codeâ€ and â€œAdd it to the postâ€ on every image).
The second nice thingy is â€œCreate mass thumbsâ€. Itâ€™s pretty self-explanatory, you can find it in the upper-right corner; it will create thumbnails for all the images in the current directory that do not have a thumbnail already created (those will be skipped). Again, this is very great for creating a gallery without going through all the images step by step.