Thank you all for the many and informative thoughts on my query. I was hoping for two things. One, that there already existed a license specifically structured around information rather than programs. And two, consensus from you folks - "Oh, you want license XYZ." :-) Looks like I'm not going to get off that easy <grin>.
I have learned I'm not so clear in my own mind about exactly what I want. The basic schism seems to be between 'always and forever free' (GPL) and 'free right now but maybe not later after some changes' (BSD/X). Anyway, thanks again for all your responses. (not meant as a "I'm finished with the conversation now" comment, I'm still listening and researching). -matt