Sheesh, hot bed Party of intolerance many of you lot. I wouldn't advertise that so loudly. :(
What puzzles me are folk who are reliable in just how late, always 3 (or 5 or 10, etc.) minutes late. Always. I can almost set my watch by them. It makes me laugh... I can understand wide variety of disasters (kids trying to kill each other, Forgot someone's lunch, DS2 goes for a 12 minute poo, alarm failed, etc.)... but if you can very consistently be 5 minutes late, why not manage to be consistently 5 minutes early? 
My how-to-be-on time tip is to not just scheduling, but allow 20 minutes for putting on coats & shoes. It's amazing how much else you'll suddenly need to do in that 20 minutes,too. And worse case scenario is you turn up at school 15 minutes early.
Lol @ Frog early in the thread, living across the road but still late every day. It's always like that, no? Even for family gatherings, the ones who live hours away get there first & the ones who live a 5 minute walk away turn up hours late.