(Cold) calling is the best option.
Also another route many people probably don't take advantage of:
- if there's a pod school in your state / city, contact them and tell them you want to shadow. More than likely they'll link you up with former alumni that you can get in touch with. This way when you call up the podiatrist, you can tell him/her your Alma matter gave me your contact info. That sounds slightly better than, "I just googled podiatrists in my area and your name came up "
Word of advice:
I think quality of shadowing is very important. My experiences so far have just been sitting and asking questions. I didn't get to see or watch anything until I posted here and members encouraged me to go back again. Now I'm going back to shadow again so I can actually watch.
So try and discuss that before hand. What will they permit you to see / not see? Will the patients be okay with it?
Have your questions written and show interest!