This morning I had the delite of watching Prime Ministers Questions on CSPAN. I was tripping out on how after someone spoke of a concern to the Prime Minister, certain people would stand up and sit back down. When Tony Blair answers the concern, people would stand up for him and sit down. What the heck was that about? Can someone explain that to me?

The standing and sitting is about trying to catch the attention of the Speaker who acts as a kind of chairman.....,he/she needs to call you to speak or ask a question - you can't otherwise.

Proceedings in the House are mired in centuries of tradition, so an element of it is also for show since it's usually determined in advance who's going to speak and ask questionsabout what.