> Does one typically put rb files in a package structure like a
> java application?

I usually identify two kinds of "packaging" (or "grouping"):
internal and external.

Internal grouping is done with modules. Put all class that are
related in one module, optionally using submodules.

External grouping is the spreading of these modules and classes
over files and directories. Which directory structure you
choose is up to you. There's no standard, not even a de facto
one.

Ruby doesn't care about files and directories, but it does care
about modules. Thus, for Ruby, internal grouping is more
important than external packing. For you, as a human, the
opposite might be true...

gegroet,
Erik V. - http://www.erikveen.dds.nl/