If I have a variable set to :test, I can convert that to "test" by calling
id2name (aka to_s) on it.

irb(main):006:0> x = :test
:test
irb(main):007:0> x.id2name
"test"

If I have a variable set to "test", how do I convert that to :test? I
suppose I could use eval()...

irb(main):008:0> eval ":#{x}"
:test

but is there a more efficient way to do this?