I just tried to add one hash to another 
with +... can't believe I never tried it
before.

It's not defined, of course.

I used update, which did what I wanted.

Should there be a +? Or an | (or)?

Maybe it's not completely intuitive...
but a hash is much like an array in 
many respects, and concatenation
seems natural to me... and the 
assumption that the receiver would
take precedence in the event of
duplicate keys also seems natural.

For that matter, | also seems natural
for this same operation... and we could
probably define & meaningfully as well.

For that matter, if we define +, could/should
we define -, making it like a set difference
based on keys?

This seems at least as intuitive as 
Array#& and Array#| (which don't preserve
duplicates -- a feature that I like but is a 
surprise to some).

Comments?

Hal