Fahrenheit 451: Metaphor Analysis

Salamander: The Salamander insignia represents the firemen of Bradbury's brave new world.  Bradbury uses the Salamander to exemplify the decrepit nature of the government.  This society, like a salamander, has sunk into the depths of depravity, and now, though seemingly modern, is really more primitive than ever.
Seashells: The seashells, or ear-radios, are used to promote the propaganda of the government and advance its agenda, or lack thereof.  Using these shells, the people drift off to sea, so to speak, and lose sight of reality.
Parlor family/television: This artificial family embodies the quality that the government seeks most to promote in its people: superficiality.  The parlor family knows nothing of reality, but instead is focused on temporal pleasures.  Like the seashells, the televised family serves as a distraction and a mindless way to occupy man's mind.
Montag: It's interesting to note that the name Montag is actually the name of a paper manufacturing company.  In many ways, Montag is a blank slate who picks up bits of knowledge from Clarisse, Faber, and finally Granger. Bradbury chuckles about this "coincidence" in his afterword to Fahrenheit 451.
Faber: Faber is the name of a pencil manufacturing company.  Bradbury also chuckles about this in his afterword.  In many ways, Faber, the instructing professor, is like a pencil, writing on Montag's notepad. On a metaphorical level, Faber symbolizes the tool (as his name implies) of learning.
Fire: Fire is an artificial substitute for the reality of truth, which can only be found in books.  Beatty dedicates his life to burning when he can't find satisfaction in the books he reads.
Mechanical Hound: The Hound is a computerized animal used by the government to punish its enemies, such as Montag.  Though Montag torches the first Hound, a second one is brought in to track him.  The Hound represents the strong hand of dictatorship.  It is the enforcer of government policy.
Beatty: If there is one, Beatty represents the mastermind behind government censorship.  He is not a robot like Montag, but a man who consciously chooses to do evil.
Sieve and Sand: The Sieve and the Sand image is used by Bradbury to explain Montag's goal to learn the knowledge he reads in books.  Like sand falling through a sieve, Montag thinks that if he reads fast enough, at least some of the books' wisdom will be retained before it falls through the sieve of his mind.
Nature: Throughout his novel, Bradbury uses allusions to nature to symbolize reality or truth.  When Montag reaches land, after floating down the river to escape, he experiences the sensation of smell for the first time.  The lifestyle of the wandering resistance also exemplifies this idea.  They live with nature, out in the country away from the city, where they experience reality.