Moveable pan controls?

Anybody know if Audacity has a way to control panning so it can move around during a song? I record music using Garageband and it definitely does not have this feature. I mean instead of just a left-right slider, the panning appears as a line you can click points on so the panning moves around during the course of the song. Five years ago I had a somewhat dinky program (called SoundEdit) and it did this. Any thoughts?

Hopefully in the next stable version. Ideally the tool would work similarly to the Volume Envelope that is already coded. Post this in the Adding Features to Audacity forum.