Your bike looks like a great single speed/fixed gear candidate. It's got the horizontal dropouts in the rear. I had a similar idea for my wife, and bought her an old women's Schwinn Worldsport, but she didn't want me to single speed it, plus I was too lazy to restore it, so it's just hanging in my garage now, hehe. Instead I built her an Xtracycle!! I hope she uses it to commute the kids to school on. That's the plan.