The 59/Fifty cap that Ash is wearing throughout the movie has the New Era logo embroidered on the side of the hat. This was not added to the MLB hats until 2016.
The Vtech branded landline cordless phone shown in Soccer Chris' parents' bedroom on December 31, 1999 was not made and released until the late 2010s.
At the party Danny sings "Thong Song" by Sisqó. However its December 31, 1999, the song was released on February 15, 2000.
While the single version for "The Thong Song wasn't released until 2000 the album "Unleash the Dragon" that contained it was released on November 1999 meaning it was possible for the song to be played during the events of the movie.
On December 31, 1999, Video MD contains VHS copies of Bless the Child (2000), The Family Man (2000), Big Momma's House (2000), and Center Stage (2000) which were released in 2000, Moulin Rouge! (2001), The Lord of the Rings: The Fellowship of the Ring (2001), K-PAX (2001), and Dr. Dolittle 2 (2001) which were released in 2001, Scooby-Doo (2002), My Big Fat Greek Wedding (2002), Mr. Deeds (2002) and Chicago (2002) which were released in 2002, and Anger Management (2003), The Cooler (2003), Secondhand Lions (2003) and Daddy Day Care (2003) which were released in 2003.
While the Apple iMac was out in 1999, the specific iMac shown to be used by Eli is a 2001 refreshed slot-loading iMac with a Pro-Keyboard.
On December 31, 1999, Video MD contains VHS copies of Scary Movie 2 (2001) and American Pie 2 (2001) which were released in 2001.
On December 31, 1999, Video MD contains VHS copy of Erin Brockovich (2000) Which were released in 2000.
On December 31, 1999, Video MD contains VHS copies of Sweet Home Alabama (2002), which were released in 2002. Planet of the Apes (2001) which were released in 2001. and Young Adam (2003) which were released in 2003.
Laura is seen creating a virus and then uploading via a USB thumb drive. This would be impossible since the first commercial thumb drive wasn't sold until 2000, at which point it would have been very expensive.