I second MusicNut's question. How and when do they contact you about interviews?
I think that what I wear to my interview will depend on where the interview is being held. I know that some interviews in my area are held in nice hotel lobbies, so obviously I would dress up a little bit more. If the interview is at a Starbucks, I'm not going to wear a dress.
I think that one thing that looks cool is to wear a long nice shirt or short dress with leggings underneath...it's a kind of cross between jeans/shirt and dress. I guess that's kind of hard to describe, but it's popular right now...I'm sure the girls at least have seen it in magazines.
One thing I've heard is not to go overboard with the jewelry. It can be distracting.