small Iphone speakers that work with phone in case

[MickeyHereWeCome!]

My dd just spent her money on the cute iPhone portable speakers that were on sale BF at Target. Unfortunately, it only works with phones/iTouches that aren't in a case. She's hoping to get the 4s for Christmas, and you better believe that one will live in a case!

Does anyone have recommendations for a small speaker set (something a tween girl would like) that works with the phone inside of a case?

I'd hate to waste time and money (and her high hopes) trying various types, but having the same problem. She doesn't want to have to remove her case every time she wants to charge it/use the speakers.

Thanks for any suggestions!