On Dec 21, 2009, at 10:55 AM, RichardOnRails wrote:
> 
> Is my speculation about this aspect of Ruby's implementation correct,
> or am I all wet?

Generally correct.  You might want to look at <http://en.wikipedia.org/wiki/Tagged_pointer> for a discussion of this overall technique.  This technique is one way around 'boxing' primitive types such as small integers, boolean values, nil, and symbols.