I want to use a combox so someone can select an option which then causes a
separate range of cells to become populated. Here's an example:

Combo box has 2 choices "New York" and "California."
If someone selects New York, then in the output range B1:B3 they see
"Albany, Manhattan, Syracuse."
If they select California then the output range B1:B3 becomes "Sacramento,
San Diego, San Francisco."

I was able to do this by using hlookup in range B1:B3 based on a table I
made off to the side, but I figure there must be a more intuitive way.

Not to complicate this even more but what I'm ideally trying to do is for
the output range in B1:B3 to actually expand if for example I chose "Texas"
I'd want B1:B5 to be populated with "Austin, Dallas, San Antonio, Houston,
Fort worth."