Loops

I needed to loop a series of spinning gears/cogs appearing at different times.

These tutorials helped me out here.
It would be perfect if I could loop full compositions, but apparently after effects CS5.5 can't do that.

http://www.instructables.com/id/How-to-loop-an-animation-in-After-Effects-CS5/

http://www.youtube.com/watch?v=XN2cEiNySpM