Ok, I just read about this on Something Awful and was amazed, so I decided to share it here, even though I'll bet some of you know this already. You can apparently attach any zip file to a .gif and keep it as a gif.

Save that to your computer and open it in WinRar. It may work in other unzipping programs, I don't know.
To do it yourself, use the Windows Command Prompt and type:
copy /B yourpicturefile.gif+yourzipfile.zip yournewfilename.gif
Make sure the new file is .gif