If you construct a statement that eventually pipes the object output to out-host using the -paging switch such as:
get-service | get-member | out-host -paging
hitting Q bails you out entirely from the demo currently managed by Start-Demo.ps1*. The end result is that you will have to restart your demo but can use #n to jump to where you last left off.
* Improved Start-Demo Script (March 06, 2007)