To add to the linked post, I have been playing around with the dry yeast starters and find that I have shorter lag times if I rehydrate the yeast prior to pitching it into a starter.
I boil .25 liter+/_ in a 1 liter flask and use the remainder of the required water in a larger flask to make the starter wort. I cool the starter wort to room temperature and then cool the rehydrating water and rehydrate the yeast as per manufacturer's instructions. I then pitch the resulting slurry into the starter wort and spin it up on the stir plate.