GIFs can be either still of frame by frame animations. Simply rightclick (or hold in shift and rightclick if you are using an older OS) a gif file, go to 'Open with'. Choose Internet Explorer and then click the 'Always use this program to open this type of file' box. Should work.
That dream where you're falling, that's fun to me...
wait, mozilla doesnt do animated gifs? you using 1.0? mozilla is awesome ever since that came out, im suprised it isnt there. but yeah just do what sushi above said, or you can do it through tools->folder options->file types.
dave :: sas|films
'Where you fall short and where I fall short, this is where I pretend I'm as tall as the sky.' -converge