Regarding my question about interpolation (sorry, David, for top-
posting, blame Google for making it the default, and me for being
lazy) thanks super Paul and David for the detailed posts, and Jeremy
for the stab at it.  I found a nice write-up on Freshmeat:
http://freshmeat.net/articles/templates-in-ruby  Hope this helps those
who may be browsing in the future for this kind of solution.

Point taken, Paul, about security.  Only trusted users are allowed
this functionality in my app.

Thanks again, all