Thanks to Mardi Brown of Georgetown Tango, this morning was the first morning after a milonga I didn't feel like a 100 year old woman trying to hobble around the house. Her recommendation of Tacco metatarsal pads (added to cushioned foam insoles) was right on the money. I can't believe how much better my feet felt. I was really starting to wonder if capsulitis was going to win and I was going to have to either quit or severely limit my dancing.
Anyone with pain in the ball of their feet should consider the Tacco line. You can get a few of their inserts, like the "drop-shaped" metatarsal pads at Austin Shoe Hospital, if you're in the area. You can also find them at FeetRelief.com . Also, please consult with your doctor if the pain in your feet is persistent, acute or if you get little to no relief from otc pain relievers.
You can get more information about foot pain conditions at Foot-Pain-Explained.com as well, but this does not take the place of medical advice.