Many thanks to the following bits and pieces of entertainment and art, both high and low:
The first of two in jokes appears in chapter three. Shawn and Cory are watching an episode of Law and Order: Criminal Intent. My sincere hope is that the episode they were watching was the one in which Rider Strong guest stars as a Muslim extremist.
A Midsummer Night's Dream
Star Trek VI: The Undiscovered Country
Star Trek: First Contact
Star Trek: The Next Generation: "All Good Things..."
Second in joke comes up in chapter five, when Griffin and Shawn get together to watch the NBC comedy block. Although chronologically, he wouldn't be watching himself, Adam Scott, who portrayed Griffin on the series, eventually became part of the block, joining the cast of Parks and Recreation at the end of its second season. (Adam Scott, by the way, is absolutely wonderful on Party Down. Watch it. Now. It's on Netflix instant streaming, so you have no excuse.)
Revelations of Divine Love by Julian of Norwich
The X-Files: primarily "Leonard Betts" and "Milagro"
The Spy Who Loved Me
The Harry Potter series
An American Tail
There are also fleeting mentions of Sir Gawain and the Green Knight, Milton, Shakespeare, and Midnight's Children.