Dist was wondering how you remove camera motion when making gifs, and I don't know if a tutorial on this already exists, so I figured I would post a quick one here in case it helps anyone else....
In case you're not sure what I'm talking about, here is a before/after (with levels)
And here is the cropped version. (This was a request by JRendell.)
I was mostly worried that the zooming would disrupt the loop. Panning is bad for loops too, although shaky camera can be a nice effect sometimes, IMO. I don't know of any way to get rid of zooming that preserves camera shaking though.
Spoiler for instructions:
I'm assuming you're working with a bunch of screencaps loaded in as separate layers (file>scripts>load files into stack...), where you've made one frame for each screencap that has only that screencap visible in it. All the following instructions are for Photoshop CS5 on Mac OS, although it should be more or less the same across different versions/OS's.
Now make a new frame, and set all of the layers you want to align (i.e. all the frames with motion in them, probably all the layers in your gif) to visible. Hit unify layer position on all of them...
select them all (shift click)
and then go to edit>auto-align.
You'll get this dialog:
If you only want to remove panning, select reposition. To remove all motion and distortion, select auto. You can mess around with the other options too if you want. Now you can delete the extra frame you added. Crop out the transparent areas and now you're done!
For more proof that photoshop=miracles, here is the most chaotic image you can reasonably expect any sort of software to align (this one was reposition only):