I spoke last Thursday at the Indiana Oracle Users Group on "The Command Line Lives: SQL*Plus and Alternatives".
I still need to get the full, S5 format presentation posted somewhere; for now, you can see the raw text of the presentation here.
It's an interesting topic, and one I'd like to get drawn more deeply into. Some nice things have been done in producing open-source command-line alternatives to SQL*Plus, including
I'm dreaming of expanding sqlpython to the point where it incorporates all Senora and YASQL's features natively. Tragically, my dreams cannot yet be downloaded from the Cheese Shop.