If you're at all interested in A Song of Ice and Fire, the books that have inspired the Game of Throne series, you may want to check out Not a Podcast. The title is a play on George RR Martin's own blog, Not a Blog.
It's way early in the podcast series, as they only have two episodes up, but I'm super excited by the way it's gone so far. PoorQuentyn and BryndenBFish are the aliases of the narrators. Both are fantastically knowledgable about the series and are quite into the material.
Between Not a Podcast and Radio Westeros, I'm fairly satiated with my Game of Thrones needs. While many fans seem to shake their fists at Martin for taking a long time between books, I have a much different perspective. Certainly, I'd like the next book to read, but there's a wealth of neat things that have sprung up in the meantime like these podcasts, not to mention forum discussions, fan theories, and deep analyses of themes and characters that we are privy to.
