I use a program called GIFbuilder on the Mac. That will do both of the
functions you require at once. If you are dealing with a gif image in
GIFbuilder:
1. open image
2. select it from the list (if it is a moving Gif there will be a
series of frames, if so select all)
3. chose the transparency selection from the menu. (I think it's under
options)
4. chose "first pixel"
5. save the file
That will make the color of the first pixel (upper left corner) the
transparent color.
To make animation you create a series of stills with slight changes
(normal animation) open a new file and bring each picture in. Set the
timing and transparency and save the series as a simgle GIF file.
Just check the menus and read the help. It's really easy.
Have fun.
Barry Hussey
barry_hussey@voyager.umeres.maine.edu