1. Creating Looping Animations
youpresent.co.uk

2. Original Yahoo Animated GIF image : Shift+F5 to watch

3. Static frame from which to create guides (press Alt+F9 to see them)

4. Infinite PowerPoint looping animation : Shift+F5 to watch

5. How it was created, 100% in PowerPoint
4 copies of the original static frame were made and each one was then cropped to the edges of each of the 4 icon pictures
4 animation emphasis effects were added to the first icon picture:
Spin 6° anticlockwise in 0.1s, after previous
Spin 12° clockwise in 0.1s, after previous
Spin 12° anticlockwise in 0.1s, after previous
Spin 6° clockwise in 0.1s, after previous
The animation painter was used to apply the above 4 animations to the other 3 icons, making a total animation time of 1.6s
A silent sound file of ~2s was recorded using Insert / Audio / Record Audio
The audio file was trimmed to 1.6s and a single bookmark added at t=0
The 16 animation effects were set to be triggered on the bookmark 2 3 4 5 6