Those are micro JST connectors with a 1.25 mm pitch. I have learned that Futaba uses them in their S3108M, S3110M, and S3111M micro servos.
Do not buy just the connectors. They require a special crimping tool. Just buy a servo extension and cut it. Try going to a local hobby store and looking for an "M-Series extension" from Futaba. You'll pay about $5 for it. Here's a link to one:
You are right. Hobby King called them JST and I did not validate it. But I do have some of the Futaba connectors, and I did check to make sure they were the same.
Carlos feel free to use anything you want from that thread if you would like to put up an article on the small "JST" connectors. It causes no end of confusion and grief since the connectors are so small it is possible to force fit some of them - but they do not make good contact as the mating surfaces on the pins are not exactly the same shape.
Also worth noting you need to check the polarity. Even although the plug may be the same, different manufacturers have been known to change the wires around. You can fry a servo or receiver easily if this is the case.
Good point about checking the polarity - I have heard of folks damaging their gear.
I'll think about doing an article, but it is only because I have known you for a long time. I don't like to steal ideas from other websites, if I can avoid it. Thanks for the heads up.