A proper scrum should last about 90 seconds per person. The person seated or standing to the left of the Scrum Master starts off and each person addresses three points:
1. Tasks I've done since we last met.
2. Tasks I'm going to do before we next meet.
3. Any blockers that require outside help.
Pigs & ChickensThere are pigs and chickens in the Scrum. Only the pigs (engineers, producers, etc. i.e. the workers) are allowed to speak. Any chickens (managers, etc) get to talk after the Scrum is over.
Real World PracticeAt Apple, I worked with fellow engineers and managers who had formal Agile training. They were masters at sticking to the three points I mentioned above. The key to keeping the Scrum from turning into a working session was, anytime a person veered away form these three points, someone would say, "Sidebar." At that point, the person who veered off track would either correct him/herself or s/he would list their Sidebar issue on the whiteboard.
After the Scrum was done, anyone could leave the meeting if none of the Sidebars concerned them. More often than not, we made it though a Scrum without any Sidebars.
Sticking to these three Scrum principles is harder than you'd think, especially when people have questions or you've accomplished a task you want to brag about. But, if you're a well disciplined Scrum, you can simply list your self-congratulatory attaboys as a Sidebar. There's nothing wrong with tooting your own horn now and then – just don't do it during the Scrum.