Auto-orientation towards the camera is a 3D technique in After Effects with a lot of uses. Sometimes though, it would be better if the auto orientation only affected the layer's y axis.

This generates perfect circular motion centered around the original position of the layer.

Creates an oscillating motion between two specified values over a specified period of time
(in seconds).

Creates an oscillating motion between two specified 2-dimensional positions over a specified
period of time (in seconds).

A simple, elegant, telecine-style color-correction tool for coloring or grading your movie.

From Adobe's LiveDocs:
You can create an expression without using properties from other layers. For example, you can make a layer revolve in a perfect circle.

In this video tutorial, Creative Cow Leader Aharon Rabinowitz shows you how to simulate airflow over an object by using the After Effects CS3 puppet tools with a particle system.