Add ‘Estimated Effort’ or ‘Start Date’ to milestones to give them some aspect of gant-style linear dimension. Moving on from this concept, you could look send notifications on start date as well as due date.

Estimated effort (what we call “budget”) has been becoming more and more important to us as well, so I’ve been working on addressing it using the API and “[budget=#]” meta tags:

http://blog.projectdetail.com/2007/08/work-on-the-nex.html

I have a similar Gantt-style report proof of concept created wth the API that links “start” and “end” Milestones together to show a span, but it will be a while before it sees the light of day.