I want to build a application on my site. in which users may design a animated graphic message. should have some effects as well.
animated gifs are surprisingly easy. I used a script I picked up at phpclasses.org to make this... You will need to decide what the background is, what the text options are and the foreground images. Have a look around at some of the scripts that already do it, you may find that for a few $$$ you can kick start the process.
Indeed, creating animated gifs is just creating a header and adding all images after each other! Usefull links: http://bunnyherolabs.com/tech/?p=35 http://www.phpclasses.org/browse/package/3163.html Have fun!