ThreadWatcher
A 4chan thread watcher and image dumper for Mac OS X.
ThreadWatcher lets you download all the images from a thread open in your browser, with a single command, preserving the original file-names. Watching a thread lets you keep track of interesting threads; Growl notifications will alert you to new posts and images. ThreadWatcher also lets you post replies to the threads that you are watching, without having to switch back to your browser.
Tags
Tag and rate images so you can always find them with Spotlight or any application that supports OpenMeta tags.
Image Dumping
The image dumper lets you post a group of images to a board, and will automatically start new threads if your thread reaches the limit.
Tabs
When watching threads, tabs allow you to keep track of many threads in a single window.
Applescript
Applescript support means you can initiate a download without leaving your browser. Example scripts are available here.