What is it? It's an audio archive of accented English from George Mason University. They record a number of English-speakers (native and non-native) reading a stock sentence, provide background about each speaker (nationality, age, how many years they've spoken English, how they learned English, residency, native language, other languages spoken, and so on), and give a phoenetic translation of their particular accent. They also provide an index of pronunciation variants common to particular accents -- reading "p" as "b", flattening vowels, and what have you. Given my geeky interest in language, language development and so on, I find this fascinating...I could listen to this thing all day. Even the "English" section (native English speakers reading the stock sentence) is really interesting, especially given that I'm currently reading this.
Take a look. Surefire fun for the inveterate language nerd.