> My main question, I guess, is this:  Is there any way that I can use
> WEBrick in a local setting only that will not open up a persons
> computer to the outside world?  I think that it could make a nice
> application base, but I don't want to compromise one's security while
> using it.
 
Bind the webserver to the 127.0.0.1 IP address and it will be only
accesible from the local host

Web-based applications are very common nowadays, I don't think anyone
will be surprised by that.

cheers,
                    vruz