[R] A model package that uses S4 methods and name spaces?

[rlee@fpcc.net]

I'd like to try and rewrite my package to take advantage of S4 methods and
name spaces.  I am presuming that S4 methods and name spaces will help me
write and maintain my package.

Can someone suggest a "model" package that uses best practices for mixing
S3, S4 methods and name spaces?  Preferably a package with multiple R
source files.

-L