E.G.
Hi K.! I belong to a group called HeightsKids, and it sounds like it would be exactly what you're looking for. Everyone who joins belongs to the main group, and we have a bigtent group (kind of like a yahoo group) page where people can post questions and information that is of general interest to the entire group (information about schools, crime, etc.). It's kind of like mamasource, but specific to the Heights/Garden Oaks area. You also have the option to join sub-groups. There are sub-groups for many different interests (politics, book clubs, expectant mothers), but, most importantly for you, there are playgroups for specific age-ranges. These groups usually meet once a week (I think...sorry, my son is 4, so we haven't gone to playgroup in a while) at someone's house or at a park. It's a great way for you and your baby to meet some new friends. Plus, the group is an incredible resource of information. I think you'll find a lot of like-minded members there. I think we even have at least two other yoga instructors! (FYI, We aren't the Attachment Parenting group that someone else posted about, but there are definitely a lot of AP-friendly families.). In addition to the sub-groups, there are also options for Mother's Nights Out (monthly), a babysitting co-op, dinner drops for families with new babies, etc.
If you're interested in joining, just send me a message. It's kind of a long explanation, and I've already gone on and on as it is!