I'll add some of my stuff too.
The reason that you burn more fat if you work out in the morning is because you are basically running on fat (unless you ate breakfeast), since your last meal was before you went to bed. This allows the body to burn more fat than exercising later (where you'd be burning the calories you had eaten earlier that day).
Also, I've found that if I exercise regularly, it is a lot harder for me to eat a lot of junk food. I can still eat some, but after a certain amount I just feel real sick. I used to be able to eat a ton of candy during the day, but if I work out consistently I feel sick after eating just 1 candy bar all day, which is quite nice.