I use the ankle ID -- I had a hospital emergency episode involving my husband 2 yrs ago, and wrist or ankle ID would probably be noticed more so than shoe (in the ER they seem to pull the shoes off quickly & throw them in a bag with other clothing items, not sure if they give them much of a look). But it's also a matter of personal preference, I can't stand to have anything around my neck, & I don't want something on my wrist getting caught up with glove removal. I wear the ankle ID on my left foot to keep it away from the chain.