Simply provide the URL for the online .gif files you want to use, as well as the URL for a single YouTube track. You can even specify exactly how long each .gif should play for. Warning! After ~10 gifs, the bitly shortener may run into problems (due to URL length)... which means sharing may be a bit tough, but it is still doable.
GifParade was very hastily channeled into this dimension by David Potsiadlo. Updates/polish/shine will be coming soon, to be sure.
Obvious inspiration & respect go out to Garrett Miller and his wonderful LoudGIF.