I know there are many classes out there for creating reflections, classes such as the one released by Lee Brimelow and so on, however there were limitations still to these classes (at least the ones that I found). For starters, your reflection was either static or was always set at the very buttom of the reflected clip. You can see in the demo I've made that the cloud(or bubbles, whatever they are) have a reflection that has distance, indicating that the cloud is floating above the surface it's being reflected on. This is part of the class, you can pass in a parameter to distance the reflection! Also, the reflection is completely dynamic and you can call the .refresh() function inside the class at any time (even in an ENTER_FRAME event) to update the reflection either constantly or on a need basis. Click the cloud in the center and start typing to watch the reflection update.

Note that you can also click and drag the two objects around.