This thread is three weeks old, but it only just occurred to me that it might be of use to someone who reads Recreational & Family but never gets over to the Folding Bikes forum:

Commuter Xootr computer tutor

It documents the creation of my current trailer/folding bike commuting setup. I now take my three-year-old twins to preschool in NYC in a child trailer, leave the trailer at preschool, then continue down to my job on Wall Street (no, I'm not a finance guy), where I fold up the bike and carry it into my office. The trip home is the reverse.

It took a lot of logistics and mistakes to get this working (and my family moved to an area safer for trailer travel in order to accomplish it). I hope the ongoing account is useful to somebody.