Dynamic View Change....
I know I've seen this somewhere before but for the life of me I can't find it. Take a look at this page:
Does anyone have any sample code?
I'd suggest using either an iFrame and changing the source, or having content in hidden DIVs and making a different one visible depending on the menu selection.
However, I know from previous experience that this suggestion will only spur someone on to dispute this and give you a better suggestion ;)