I live in El Cerrito, too. Our boys are 7 & 2.5 yrs. Si your son at all interested inmartial arts? There are several studios in the area. Go to Park & rec on Moeser to see what classes they're offering for winter & spring. Check out Albany, too, on Marin. Is he intersted in skate boarding? Teere's a skate park on Harrison just off San Pablo behind the McDonalds. And always my favorite....the Downtown Berkeley Y on Allston across from the main PO. We've been members here for ages. They are very family-friendly & offer classes at very reasonable prices...sports, martial arts of different kinds, swimming lessons. They also have open swim times throughout the week as well as offering Friday night activities. What about your your mom getting to know some of the parents? It might be awkward for her but you're son will be there a couple more years so it would be good for him to have some bonds at school. He'll probably go to middle school wn/most of these kids, too. Maybe she could encourage him to ask a friend to play after school & take them to a local park. Hope this helps & good luck!