As part of the promotion for the movie at the Comicon in San Diego, promoters threw a huge "Welcome" party open to the public, with barbecue, beer, skateboarding demos, and a wall where people could write "subjects" they'd like to study. Justin Long and other cast members mixed in with the crowd, to the point that you couldn't pick them out.
During the hot dog costume scene, Schrader mentions how James Garfield even wore the suit, though not a member of the fictional BKE fraternity in the movie James Garfield was in fact a member of the Delta Upsilon International Fraternity. Plus, the earliest possible date for the invention of hot dogs is 1870. James Garfield graduated from college in 1856 - fourteen years before hot dogs were supposed to have been invented.
There is a character named Rory who has been working her whole life to go to Yale. In the TV show Gilmore Girls, the main character, named Rory, has been working her whole life to go to Harvard but then ends up going to Yale.
Instead of attending Harmon as mentioned in the movie, James Garfield actually attended Hiram College in Northeast Ohio. Garfield later went on to teach at Hiram and become the President of the institution.
The trivia item below may give away important plot points.
Although the final scene of the movie occurs in front of the Ohio State Board of Education, in the State of Ohio, the proper venue would in fact be the Board of Regents. The Ohio State Board of Education regulates primary and secondary in the state.