You can already do it using the advanced search engine, which is a great tool and very powerfull
Try searching for the code used: eg;
[NSFW][/NSFW]
[IMG][/IMG]
To make it easier to find, have the search displayed as posts, rather than threads.
For example, a search for all the images posted in The Lounge, for the last week would look like this...
http://img694.imageshack.us/img694/1544/searchimg.jpg