Thanks for the feedback Tom, I am new to youtube, and it is the first video that I have posted there. I think it would be nice if youtube also allowed animated gifs, and flash as formats, as it would greatly reduce the bandwidth that they are trying to save by disabling the repeat function. This particular file is made up of 9 frames at about 74k each at 640x480, and then the frames are doubled to give the up and down sequence.
A flash file would be a fraction of the 26.1 meg for one cycle as in this avi file, and 246 meg for a reasonable number of iterations as an avi file.I am looking at the best mpeg format, as this reduces the file size dramatically. I will do some reading up on the best formats to use.