The Diffy family — Barbara, Lloyd, Phil, and Pim — are your average 22nd century family. Which is a lot like your normal Nuclear Family, except with aliens. During their vacation through time, their time machine breaks down in the present day. The family must rough it out in the 21st century while trying to get back home — all the while not telling anyone that they're from the future. (Well, anyone except Keely Teslow, Phil's 21st century love interest.)This is a Disney Channel show, which of course means one of the girls sings for the Disney Records label. (In this case, Alyson Michalka, who plays Keely, teams with her younger sister A.J. to form the pop group Aly & AJ (Now known as 78violet.)This is the last Disney Channel Original Series to date not to be produced by It's A Laugh Productions, which almost certainly explains why it was Screwed by the Network (in the form of premature cancellation - it didn't even make 65 episodes) in favor of all the other shows that were. It lasted from June, 2004 to August, 2006.
All Girls Want Bad Boys: Pim finds her soul mate in a classmate who shares her penchant for pranks and loses all interest when he saves her from a humiliating scene instead of making fun of her.
Artistic License - Physics: In "Good Phil Hunting", Pim can (apparently without the use of any gadgets) build up enough of a static charge to go all Emperor Palpatine on anyone who touches her. Pim being Pim, she ends up using it to get revenge on Candida.
To add to that, Doug Tuber (one of the creators) confirms that he and his writing partner Tim Maile (The other creator) were hired by Disney to write the Phil of the Future finale movie. Doug say's it was a very detailed and funny and romantic outline. Disney decided not to produce it.
Pim (trying to sell the Diffys' house): Notice the staircase, which doubles as a toddler-friendly double black diamond toboggan run.
The Danza: Joel Brooks guest stars occasionally as Joel Messerschmitt. This is probably due to his first name being pretty much irrelevant, what with him being a teacher who we only see around his students.
Dance of Romance: Once in "Neander-Phil" and again in "Get Ready to Go-Go"
Dawson Casting: Averted with Alyson Michalka (16 or 17 by the season finale) and borderline with Ricky Ullman (19 or 20 at the end of the series). A definite example is Ashley Drane, who was 24 when she played Grace in "Stuck in the Meddle With You."
Failure Is the Only Option: Lloyd purposefully procrastinated/sabotaged the systems because the family enjoyed the 21st century so much. He really could've just fixed it at any time.
Fate Drives Us Together: Implied with Phil and Keely at several points, including Keely placing her childhood music box into the school's time capsule that is later found by Phil's mother and used when he was a baby.
Hilarious Outtakes: At the end of the episode “Halloween” and “Broadcast Blues”.
Holding Hands: Phil Diffy and Keely in the finale episode "Back To The Future (Not The Movie)". The irony is that they've probably held hands a million times before as friends, but once they decide to become a couple, they can't get the logistics right.
Idol Singer: Aly & AJ (Now known as 78violet), one half of which is the show's female lead, Alyson Michalka.
Large Ham: The guy who plays Messerschmitt quite obviously has way too much fun with every single line he says, especially in "The Giggle" when discussing the Omicron Gambit, his legendarily hard...make-up test. It's all Played for Laughs, of course.
May-December Romance: Accidentally and played for laughs in "Age Before Beauty". When Keely ages herself with a future device and catches the romantic attention of Vice Principal Hackett, Phil must step in and pretend to be her boyfriend to deter him. Unfortunately, he accidentally ages himself to about 80, to Keely's 20-something.
Meet Cute: Phil and Keely, though Keely didn't know. The entire episode "Christmas Break" is devoted to how they met. Keely was the Pickford Yuletide Star Princess in charge of the town's yule star (obviously) to be used in a tree lighting ceremony. Pim breaks the glass Yule star, and Phil, feeling badly about it, goes back in time to fix it. Through a series of unfortunate events, he ends up going back in time several times to save the star, eventually succeeding. Keely finds this sweet, Pim...not so much:
Keely (about the Christmas tree star): Ooh, that's my favorite part.
Phil: I know, you were the Pickford Yuletide Star Princess, after all.
Keely: That's right! Wait...we didn't even know each other then. How did you know about that?
Phil: Well...you see...I actually met you before you met me.
Pim: Met her? You followed her around like a pathetic puppy.
Keely: Really?
Pim: He was like 'Oh, we have to help the pretty crying girl!'
Puppy-Dog Eyes: Keely gives these to Phil in episode “Age Before Beauty”, "The Giggle" and "Dinner Time".
Put on a Bus: Tia, Bradley Benjamin Farmer, and Seth Wassmer.
Race for Your Love: Phil and Keely end up doing this in the final episode, though with far different results. Keely suddenly changes her mind about seeing Phil and his family back to the future and runs to catch their time machine before it leaves. She's unsuccessful. The second time is Phil, who has his father return their time machine to about five minutes before Keely does her race and he catches her at school to say goodbye (cue The Big Damn Kiss)
Red Stringof Fate: Played with with Phil and Keely. In "Time Release Capsule", Keely puts her own childhood music box in the school's time capsule; Phils mom finds it a century later and plays it for him as a baby. It's revealed in "Christmas Break" that Phil was the one who broke the time machine, but that if he hadn't stopped to help Keely, the family would have been caught in a massive time-storm and gotten lost forever.
Reed Richards Is Useless / Plot Technology: Justified, since they have to maintain the masquerade and minimize their impact on the outcome of history, they can only use the future tech to solve the day's problems.
Relationship Upgrade: Phil and Keely in the season 2 finale which ended up being the series finale "Back To the Future (Not The Movie)".
The Rival: Bradley Benjamin Farmer and Candida are rivals of Pim.
Science Fair: Phil and Keely in the episode “Milkin’ It”.
As well, in "Good Phil Hunting", Hackett is briefly shown writing equations on a clear, glassy surface, mimicking similar memorable moments from A Beautiful Mind and Good Will Hunting.
In the same episode, Hackett asks Phil what the first rule of AV club is. Naturally, it's "Don't talk about AV club." There's also a reference to Fermat's Last Theorem; apparently a problem known as Foucalt's Last Conundrum is highly difficult in the present day, but is basic material in 2121's third grade.
When Mr. Hackett wakes up from the shock of Keeley "solving" said Conundrum:
In "Dinner Time", Barb's trying to prepare a typical American dinner party. Her research leads her to believe that it should be 50's style, right down to the clothes. Phil ends up looking like Fonzie, right down to flashing the classic double thumbs up right after being zapped with the Wizard and immediately lampshading it.
"Dinner Time" also slips in a reference to The Wizard of Oz, when a pair of prospective buyers for the Diffy house ask if it has suffered a twister of "Oz or greater magnitude".
The Big Damn Kiss: Phil and Keely's kiss in "Back to the Future." They kiss on the school's CCTV and get a standing ovation from the entire student body.
The Matchmaker: Keely in "Stuck in the Meddle with You".
Timey Wimey Ball: They play with the concept of Temporal Mutability a lot, most notably in "Time Release Capsule" and "My Not-So-Great Great-Great-Grampa".
Uncanny Valley Girl: Debbie Berwick. We learn later that she's actually an evil robot bent on world domination via cupcakes.
Undercover As Lovers: At one point, Phil and Keely use the Wizard to masquerade as his parents to fool their snooping neighbor, Mr. Hackett.
Valley Girl: This is how Keely and Tia are first introduced. Tia stays this way until she leaves the show, though Keely moves away from it a bit as the show goes on.
Worthless Yellow Rocks: Diamonds are a waste product in the future, but aluminum foil is apparently invaluable.
Very much justified. Aluminum is valuable even today (which is the motive behind pop tab collections), while diamonds are easily manufactured from common carbon.
Word Of God: Doug Tuber stated that after seeing Ricky Ullman & Alyson Michalka's chemistry on screen he knew Phil and Keely were destined from the start of the series to become more than friends.
Young Future Famous People: Though the youthful famous person is fictional, Phil runs into the inventor of the Wizard in his high school during a career placement test.