Dye Hard: Kari is actually more of a brunette and in some episodes her natural hair color can be seen (such as in the pilot).
Edited for Syndication: They also like to play the stuff that got cut in an end of season wrap up. Or, as stated before commercial breaks, most of the cut material winds up on the website. In one first-season episode, most of the "Octopus Pregnancy" segment (including all the testing) was chopped out of the US release.
Executive Meddling: Largely averted. The Discovery Channel executives give the MythBusters a lot of creative freedom and basically let them call the shots. The only times they step in to block a test is really when they feel that the test might offend their sponsors or provoke legal action. The channel's insurance agents have also squashed or put serious restrictions on a lot of tests due to safety concerns for the crew. Or perhaps it would be more accurate to say concerns for the hosts. They once vetoed Adam doing a stunt, but they were fine with Tory doing it.
This includes one that actually jeopardized a myth they were trying to do. They were trying to see if a car could be turned over and flung into the air by the wind generated by a jet engine. The company that had loaned them the jet took it back due to them being worried that something might hit the plane and damage it, despite the fact that the car would be moving away from the plane.
They eventually found an airline who agreed to lend a plane to perform this very experiment, which they tried on a car, a school bus and a small airplane. And it was awesome.
Early in the show's history, Discovery execs pushed for Jamie and Adam to have American Chopper-style Docu Soap arguments on camera. There's a couple episodes where this made it into the finished show (the Quicksand episode notably), but the two of them finally told the execs no, that behavior wasn't professional, and they weren't going to do it any more.
Played straight at least one time (though not shown on the show itself). Basically, they were going to do experiments on how easy it is to hack RFID chips, and per policy, called up the manufacturers (Texas Instruments) to schedule a conference call to talk about it. When they actually sat down to the scheduled call, lawyers from most of the larger credit card companies were involved, saying they were not to do the episode. Discovery could not afford to lose the advertising, and they had to cancel the episode. You can see Adam explain it at The Last Hope hacker conference here.
Funny Character, Boring Actor: The main reason Jamie brought Adam in on the show is because he is naturally The Stoic and uninteresting by himself. Adam's high energy level and their good working relationship manages to mask this on camera, but they've also said the editing makes Jamie seem more quick-witted and eloquent than he really is.
Alton Brown recently appeared in a food-centric episode.
Hey It's That Music: Sharp-eared gamers may recognize one of the musical snips they sometimes use between shots as coming from the soundtrack of MechWarrior 2.
Missing Episode: A lot of general footage and some mini-myths are left out of the show, many of which they put on their website; the show then invites viewers to visit said site to see what was left out.
One famous myth, though, was actually kept from airing at all because it was deemed a little too risque/immature. It involved the flatulence myths and testing if you can actually set your farts on fire. Confirmed, but most of the footage is of Adam spread eagle on a specialized chair holding a lighter near his crotch. Nobody really wants to see that. They finally did the experiment on an episode of Craig Ferguson which the cast were guests on. It worked. The segment itself finally partially aired during the "25 Best Moments" special.
And at a live Q&A three years ago, Jamie mentioned that they once tested the myth of whether a cardboard cereal box was more nutritious than the cereal itself. The test as a whole did air, but one experiment which was cut involved feeding three mice cardboard pellets with a little sugar-free sweetener for taste. The next day Adam and Jamie, instead of finding three mice, discovered one fat mouse (and some remains)... Discovery Channel (or the producers) decided not to air the footage so the Q&A is the only way fans learned of it.
The footage from the errant cannonball incident will not be released, in accordance with the wishes of the family whose house said cannonball went through. The myth itself aired in late 2012, but was preceded by a short commentary by Grant, Kari and Tory explaining what happened. They showed the build-up to the incident and showed the cannon being fired, but did not show the aftermath. Then, the team explained what had happened afterwards and then the episode showed them continuing the myth months later at a remote quarry where there was no risk of a repeat of the incident.
Plans were in place to do an episode about RFID tags, with research already underway. Legal counsel for every credit card company in the world explained to them exactly how much it wasn't going to happen, and it's never going to happen.
The Mailbag Special was another instance, like the above-mentioned "lighting farts on fire" myth, where previously unaired footage was finally shown, this one concerning a myth that a van filled with flammable gases could blow up when someone used a keyless remote. The myth never made it to air because it was confirmed too quickly — the team went straight to a full-scale test and immediately blew the van up with the remote, leaving no need for small-scale tests or replicating the results through other means. They didn't believe it would work so well, but Grant's comment really should've tipped them off.
Unfortunately, on November 7, 2012, Discovery shut down all show discussion forums, including Mythbusters', and with the unofficial fan site having been shut down several years ago due to "creative differences", there is one fan site used by researchers for myths, but is largely unknown, for whatever reason.
The Mythbusters "Submit A Myth"/discussion page has been officially reinstated here, via a Disqus comment feed.
Old Shame: Adam's biggest acting role is revealed to be: a teenage stockboy in a toilet paper commercial.
Adam Savage has actually used the word 'trope' on the show. He also has a bit of a tradition of going to conventions in concealing cosplay so nobody knows who he is; among others, he's gone as No-Face from Spirited Away and a Nazgul. He also owns a replica Mark 1 Iron Man armor suit from the movie which he got on eBay. He is a honorary member of the 501stnote a Star Wars stormtrooper cosplay troupe, according to the "Revenge of the Myth" episode.
Grant has gone to numerous conventions. He even dressed as the Tenth Doctor at some point.
The Other Darrin: Occasionally, the team will pass off one of the Simulaids as Buster for some unexplained reason.
The Pete Best: Scottie Chapman left the Build Team just when they got a bigger role on the show, and was replaced by Grant Imahara.
Star-Making Role: A few years into the show now, Adam and Jamie are big draws as speakers and have hosted a booth at Comic Con at least once. Failing that, they are fairly recognizable to most people, if not by name, at least as "the MythBusters".