Also, I suggest, start on time, no matter what. If you have to read in missing people, get started. You are going to have wait or go back anyway, why not show the cast we are starting on time no matter what . . . so let's get started[/quote]
I couldn't agree more! Tell anyone who asks that if they have been scheduled then yes they are required - dont feel bad about doing this - and then start on time no matter what. Explain this strategy to the Director in advance if you need them to be on board to make this work. If not just do it. Starting late because some people are late is a self perpetuating cycle where eventually noone bothers to arrive on time.
And as Matthew also said - this is a problem in varying degrees at many different levels of theatre practice, not just community - but if you set the tone by your own demonstration of committment and professionalism you are less likely to have problems - ie EXPECT them to be committed and behave as if they will be.
I also agree with the phone call strategy. If you have an asm who can do it - ring everyone who isnt there right on start time and ask why they are not there - I usually start by asking if everything is OK (ie that they havent had an accident )- if they have had a problem you dont want to be being stern with them about lateness - that tends to end badly

Hope things are improving for you
ChaCha