David Thornburg reaches back to the early days of the telephone to craft an excellent analogy explaining why net neutrality matters.
Now that analog voice signals have moved to digital broadband bit streams, the idea of equal universal access is under attack. If Congress allows telcos to determine tiers of service for individual packets (not for overall service as is done today), your DSL provider might decide that you should get Yahoo really fast, and Google really slowly. This is exactly like having the telco decide you should get your pizzas from Dominoes, not Pizza Hut, and making phone calls to the latter full of noise and busy signals.
What makes David’s history lesson work so well is that even someone who is clueless about the internet (like Ted Stevens, chair of the Senate committee responsible for writing legislation on that very subject) understands dial telephones.