Agree with above post....
also, I would suggest that you pursue research in the most competitive field you are applying to, or find a common thread between two. For example, if interested in Ortho, Peds, and Medicine, the specialty where field-specific research would be most helpful is clearly Ortho... the other two are less competitve and research by itself will carry significant weight regardless of field. If you could do research in, say, pediatric orthpedics, you can cover 2 of the three. Or for example, you're interested in ortho, Neurosurgery, and ENT... consider a project involving head/cervical trauma, facial fractures, etc. Multiple fields covered by a single project.
You probably get the idea...
