Knuckles follows this same routine: little mischief maker in the first few years, a little punk in his pre-teen years, a swearing teenager in his 14-15 years, and finally, an adult that finally grows up and realizes his mistakes.
one, you make an animated gif. they'll all look like crap, but they'll loop every X seconds.
two, you can try using this site, though i'm not sure if it would work. maybe if you extract the link from the HTML code and use it as the banner's link, it would work. if it does, however, it'll randomly show one of the three (or more, if you add more) images each time it's loaded. so if you keep pressing F5 or browsing through topics, the images will change.
Or this site is much better.All that site did was upload the banners. It didn't give me any edit tools.