Scenes From An Alternate Universe Where The Beatles Accepted Lorne Michaels? Generous Offer
This has been getting some (well deserved) coverage in the blogosphere. I love AU history, and this is a lovely example, with a lot of detail being packed into a (comparatively) brief narrative. If you squint, you might even see some faint hat tips to Dr. Who or Quantum Leap.
Edit: Link fixed.
