Let them stay home and follow you around in all the menial, boring activities like grocery shopping, stay in line at the bank and the post office, go to doctor's appointment and visit your old antie. Trust me, next day he/she will rather go to school!
My 4 y/o likes to go grocery shopping with me and to the bank! He eats a banana at the store and reminds me what to buy. At the bank he makes a picture to give to one of the bank tellers. And at the coffee shop he gets to buy skittles with a quarter he found in the car. Ok, so I'm making this all to fun! What I do is let him decide if he wants to stay home with me or go to preschool on Fridays, because I don't work that day. I'm sure as he gets older he won't want to go shopping with me!