Mermaid Costume...Anyone?

Some times...I just hate the world wide web. I need to get started on my son's and daughter's halloween costumes if I'm going to have them done by October. My little girl really wants to be a mermaid. The only patterns I can find for them are either really ugly or hoochi-mamma-style, and I can't do that to my daughter...not to mention I would have no idea how to down-scale the pattern. So I'm asking...Does anyone have any easy ideas for a pretty mermaid costume that's suitable for a little girl?