The girls in my first childbirth class formed a playgroup - we've been getting together every 2-4 weeks since my 3 year old was 6 months. (I can't believe it's been 2 1/2 years!)
There's only 5 of us, but there's 9 kids now, soon to be 10 (everyone has 2 except one girl and I'm about to have 3). We started out meeting at each other's homes, but since we added seconds and since the older kids turned 2, we've been meeting out at play areas and parks and places like Chuck E Cheese.
We've only ever gone out moms-only twice. I went the first time when we all only had 1 (and I think the kids were around 9 months?). The second time is scheduled for this month. My kids are currently 3 years and 1 1/2 so I'm fine w/leaving them w/dad. He'll probably try to con his mom into helping, we'll see...
I wish we did it a bit more often. I probably wouldn't hang out w/these moms other than b/c of our playgroup, but when I just wrote down we've known each other for 2 1/2 years, I couldn't believe it. I hardly know these ladies at all! They definitely aren't AP: only one other BFs, one of them uses daycare (she doesn't need it), one is a total flake and her kid is way obnoxious (I'll never have another playgroup in my house EVER b/c of the way he behaves (not his fault - HERS!)). BUT it's so nice just to have a playgroup, I'm a SAHM and don't have relatives w/small kids, so this is my kids only socialization other than random kids at parks and play areas.
I wish we could get out just us every 3 months or so. Like I said, I probably would never hang out w/them except outside of our playgroup, but it's nice to have moms to relate to on any level and I think if we got together more outside of playgroup, we'd know each other better and I might feel more like they were friends than "the playgroup moms."
Well, this is long, but all my 2 cents are...
WOHM married to SAHD, living the dream w/our: 3 girls (14,12,10) and 3 boys (7,5,3) and tie-breaker due Jan 2014