Need help

Am making a new banner for the blog and I'm trying to find out if theres any program that will do the GIF-ing for me. As in, I input the images and it makes a pre-made slideshow GIF image for me according to the dimensions I want.

If anyone knows of such a program, let me know.

Also, today was a typical Sheep-takes-a-green-form Day.

-HARUHIISM