I don't recall this ever happening to me, however I have had the experience of walking past someone at the shopping centre who is wearing something I also own and I usually just smile to myself and check out how she is wearing the item. I did have a colleague who bought the same shirt as me (it was quite distinctive in its pattern) with my encouragement as it looked fab on her. She very kindly only wore it on Friday's as she knew that was the day I wasn't in the office:) And once when I as co-ordinating an event, a colleague turned up in almost the exact same dress. It wasn't but it they were so similar, however she was wearing bare legs and pumps with it whereas i was wearing leggings and strappy bootie/sandals... we just laughed and complimented one another our good taste:) Our jewelry etc also made our looks quite different.

Kelly, that it a beautiful skirt.

The same outfit thing is quite likely to happen to me as I live in a smallish town with limited local shopping. Just the other day I went over to a good friends house with my black puffer coat on only to have her answer the door in the same coat! (different lining, as she had this years model and my was from last winter) I seen at least two other mums at school with this coat too.
A lady at church and I have the same blue patterned dress but have managed not to wear it at the same time. We always have a laugh over it and she says everytime she she puts it on she hopes I haven't (mine has faded so I just wear it at home now anyway)

Several local boutiques sell ruffled leather jackets. I have seen 2 people I know wear them in pink and another in red. They are quite distinctive looking. While the jackets are very attractive, their ubiquity in my town (as well as the cost) has put me off buying them.

I can't remember this ever happening.

But I'm going to my husband's high school reunion tonight in a Karen Kane dress. If another woman shows up in it, it's gonna be a smackdown! LOL