There's a lot of overlap between folks who love Fallout 3 and folks who love Rock Band. Here's some news that caters to the inner portion of that particular Venn Diagram: Nerd-rock duo Kirby Krackle's Fallout tribute song "Vault 101" is now available on the Xbox Live Rock Band Network Store.
If you'd rather purchase the track in a non-interactive fashion, you can grab it off the band's official site -- or, if you're really short on time, you can watch a live performance of "Vault 101" in the video posted below. It's actually pretty catchy! Catchier than you'd expect a song based on a post-apocalyptic action-RPG would be, anyway.