A couple methods for you.
1) consult your local yellow pages and call one to set up at least a meeting to just talk and hopefully an opportunity to shadow. Don't just come out and request recommendations over the phone. Remember they have no idea who you are, and you'll get a crumy letter. I haven't been turned down yet, but others have, so keep trying if at first you don't succeed.
2) Next time your sick make an appointment with one. Then talk while your there. Perhaps you can set something up when your well.
3) Ask around with friends and family to find out if anyone has a DO that they see regularly. They can then give you the hook up. This was one of my methods (very successfull).
4) If your well aquainted with any MD's ask them if they have a DO friend that could help you out. This was another method that worked great. One of the MD Radiologists that I work with introduced me to a good friend of his that was a DO. Told him that I wanted to meet and talk with him and also vouched for me.
I hope this helps, good luck. Oh last piece of advice. Don't be pushy, but try to make it clear that you have a deadline to meet with those letters. Speak with them well in advance (at least a month). That'll will give them plenty of time. Also, bring a portfolio with you to give to the doctor. That will go a long way towards giving you an excellent letter.
Good Luck
