How do I change the milestone sign in the gantt chart to be larger?
Following works in MS Project 2003 (I know it's an old version, don't blame me, blame the company :-) )
Right click on the milestone icon and click 'format bar' You get a popup screen in which you can select the icon you want to use.
I don't think it possible to make it bigger though, only change color, shape or type... Personally, I don't think it makes any sense to make it bigger, as it is the whole Gantt chart you zoom in/out... not a specific symbol...
Perhaps in later versions of MS Project, this is possible...