On the web, they seem to work pretty well for image galleries. Although I think it's important that you can dismiss the lightbox by simply clicking anywhere out

On the web, they seem to work pretty well for image galleries. Although I think it's important that you can dismiss the lightbox by simply clicking anywhere outside the image. In general, modal dialogs are suitable for operations where it helps to have contextual information in the background, but you don't need to interact with it. A 'Save' dialog is a common example. This thread on UX exchange has some more thoughts and examples: http://uxexchange.com/questions/1153/when-should-you-use-a-modal-dialog-box http://uxexchange.com/questions/1153/when-should-you-use-a-m...