Having just completed an article on Callbacks in ActionScript and having previously written about custom events in ActionScript I thought I would take a few minutes and contemplate on the difference between the two and when I see each being useful. Bear in mind that I still have only a small amount of experience in Flex and ActionScript. This is more of a straw man post than a definitive guide and I welcome thoughtful criticisms and comments.
Both callbacks and events allow us to respond to events, the difference is how and to an extent, how complex. Custom events are a bit more complex to code and maybe that is why I see callbacks as more useful on a day to day basis.