What I do to get ToonStruck animations in gif is not an extraction but the result is quite good.
Programs you need: DOSBox (I use the last version 0.73), some video converter (I use Total Video Converter) and VirtualDubMod. DOSBox can capture screens, videos and music but in the last version I had problem to know the location of the folder where those files were saved. So if you don't know it too, run DOSBox with some game and press control-F5 (to capture the screen) and then do a search of files named "main" and you must find something like main_000.png. The containing folder is the searched one.
1. So the first thing to do is run DOSBox with the game and arrive to the point where the animation is displayed. Then you must be sure that you can see the game fluid and with the right colors, otherwise the video will look bad too. Well the command Control-Alt-F5 starts to record the video and the same combination stops the record, so record a video as long as you want for caution with the animation.
2. Then open the video converter and find the video in the captures folder (must have a name like main_000.avi but is a very strange codec) and convert it to some format accepted by VirtualDubMod (I convert them into MPEJ AVI).
3. Then open the converted video in VirtualDubMod and find the best part where the animation looks better and cut it with "Set selection start" and "Set selection end" (if it's a looping animation make sure that the starting frame and the ending frame are the same or quite similar).
Then if it's not an animation of the full screen you have to resize the margins. So go to Video>Filters and you will see a button called Cropping that can be used only when some filter is activated, so go to Add and choose the filter called resize and push ok until you return to the filters screen.
Now you can click to Cropping and you will see the screen and will be able to modify the margins.
Finally make sure the result is what you wanted and go to File>Export>Animated GIF.
The gifs can be uploaded to imageshack. I hope it will be useful, post any question / problem.