Now that school is starting, you guys (whether you're an extrovert or a SAH parent or both) have the chance to do a really good deed.
If you're a SAH parent, you could buddy up with a WOH parent to make sure s/he knows what's going on in the classroom. Yes, you're supposed to get all the same notifications and stuff sent home, but any SAH who's been in any school for a few weeks know that the ones who can put in face time know lots more about what's coming up and what's really going on than they ever send home.
If, perhaps, a WOH mom should hand you her business card with contact info, it means she really wants to be in the loop and wants to be your friend, and you'd be doing a super-good deed by keeping her connected about what's going on.
(I'd like to give a super-special thanks to Brandy, Kim, and Amy for telling me what was going on all last year.)
If you're an extrovert like me, please be aware that there are introverted and/or shy parents in your class that would love to be your friend but won't make the first move. They are fabulous, interesting, funny, snarky, trustworthy people who just aren't hard-wired to approach you. You'd be doing them and the world in general a big favor by approaching them and including them so they can give what they have to offer. Because they're not as enthusiastic about meeting a zillion new people as I am you are, don't give up if your first two volleys aren't accepted.