public classes within public classes

Hi all,

I just came across some code that has embedded classes within classes
and was surprised because I didn't know that was a feature of the
language (guess I have been doing Java longer than I thought - since
1.1).

Example

Public class MyClass {

 // methods and such

  public class MyInnerClass {
   // methods and such
  }


}

Anyway, what I am wondering is if there are any huge drawbacks to going
this route.  I came across it in the code that the Web Interaction
Wizard in WDSc created for me.  In this specific scenario it seems to be
a good fit because the outer class defines an RPG program to call, and
the inner classes define the input and output data structures that are
passed.  

Thoughts?
Aaron Bartell