1. Introduction  
2. Observations  
3. Results and Models  
3.1. SiO Jets and the Shock-Forming Model  
3.2. CO Outflows and the Wide-Angle Wind-Driven Shell Model  
4. Discussion  
4.1. Application to Other Sources  
4.2. Jets and Outflows  
4.3. Jet Knot Timescales and Mid-IR/Sub-mm Light Curve Variability  
5. Conclusions