What is it about cameos we love so much? The surprise factor? The chance to see actors and real people sending up their set-in-stone images? Or just the hilarious disconnect we get when someone as famous as, say, Harrison Ford, strolls into a film that's clearly not ever going to show up on his official resume? How about all of the above?

We tried to keep some of these plot twists intact for you here, but if you don't want to know which mellow musician went blue in 'Funny People,' which unlikely 'Saturday Night Live' alum popped up in between Nazi bloodbaths -- or which comedy legend made this year's most-talked-about (and best kept secret) cameo -- then for the love of Mike Tyson, don't read any further! What is it about cameos we love so much? The surprise factor? The chance to see actors and real people sending up their set-in-stone images? Or just the hilarious disconnect we get when someone as famous as, say, Harrison Ford, strolls into a film that's clearly not ever going to show up on his official resume? How about all of the above?

We tried to keep some of these plot twists intact for you here, but if you don't want to know which mellow musician went blue in 'Funny People,' which unlikely 'Saturday Night Live' alum popped up in between Nazi bloodbaths -- or which comedy legend made this year's most-talked-about (and best kept secret) cameo -- then for the love of Mike Tyson, don't read any further!

(IN OTHER WORDS ... SPOILERS BELOW!)



10. Arnold Schwarzenegger in 'Terminator Salvation'
A 'Terminator' without Ah-nuld? Unthinkable! But just when we counted out the Governator for the fourth film in the series, there he was, in all his original model glory! Well, not the whole glory, just a quick glimpse of naked flesh-over-metal as John Connor (Christian Bale) sneaks into Cyberdyne HQ to shut down those pesky cyborgs. When Arnold said, "I'll be back," he meant it. Now, if only he were as good about keeping his campaign promises.


9. Bruce Hornsby in 'World's Greatest Dad'
Robin Williams is hardly the world's greatest dad in this black comedy, but his poetry-teaching character Lance is definitely the world's biggest Bruce Hornsby fan. So it's kind of a no-brainer that Hornsby himself stops by in a hilarious cameo. Except that Lance's son, Kyle, (Daryl Sabara) already slammed the singer-songwriter as a "f*g." Then again, Kyle calls everyone that, so maybe Hornsby figured, that's just the way it is.



8. Eminem in 'Funny People'
We can go along with the premise that comedian George Simmons (Adam Sandler) has a lot of famous friends, but we still weren't expecting him to turn to a certain Detroit rapper for some surprisingly solid career advice. The real Slim Shady shows up when Ray Romano (who also plays himself) snaps a photo of him on his cell phone and Marshall threatens to "f**k him up." Judd Apatow told the San Francisco Chronicle, "We made up as we were going along ... I kept worrying, 'Am I going to offend this guy?' Then I thought, 'He wrote songs about killing his wife and his mother. I don't think I could pitch him a joke that would make him mad at me.'"


7. James Taylor in 'Funny People'
In his cameo -- which reportedly began with director Judd Apatow asking the musician to play on-set to put wife Leslie Mann at ease in a love scene with star Adam Sandler -- Taylor plays against his ultra-mellow image, showing off a helluva temper and a lot of words you can't say on the radio. Of course, it's not the first time Taylor's sent up his folksy image. On the 1994 'The Simpsons' episode 'Deep Space Homer,' he lectures Buzz Aldrin, "Listen, I'm not as laid back as people think. Now here's the deal: I'm going to play, and you're going to float there and like it."


6. Thomas Lennon in 'I Love You, Man'
'Reno 911!'s Lennon brings the funny as one of Paul Rudd's "man dates" that goes horribly wrong. Doug thinks he's in for romance, not bromance, and plants a full kiss on the unsuspecting Peter. Their smooch was nominated (along with 'Twilight') for Best Kiss at the MTV Movie Awards. "You're not going to find anybody down in Times Square that's gonna run up and wanna kiss me," Lennon told VH1.com. "Rudd did, and that's points for difficulty. We did that kiss no less than 30 times from three different angles. I went for tongue. A lot of people wouldn't have done that."


5. Mike Myers in 'Inglourious Basterds'
When your career's tanking and people are openly talking about what a nutcase you are, what better way to win 'em back than with a well-placed cameo in one of the year's hottest films? It worked for Tom Cruise in last year's 'Tropic Thunder,' and by Jove, it worked pretty well for Mike Myers, who trots out his best British accent as General Frenech, who gives double agent Archie Hickox his mission. A few more understated cameos like this, Mike, and we might just forgive you for 'The Love Guru.' Maybe.


4. Harrison Ford in 'Bruno'
The superstar -- easily the biggest name captured by Sacha Baron Cohen's guerrilla approach for his second major docu-spoof -- appears only long enough to utter two angry, choice words to the outrageous filmmaker. Either Ford was in on the joke (and we like to think that the guy who improvised the "just shoot the swordsman" scene in 'Raiders of the Lost Ark' has a pretty decent sense of humor) or didn't care enough to demand that the clip be cut. At least Bruno didn't call him "Junior!"


3. Leonard Nimoy in 'Star Trek'
Talk about big ears, er, boots to fill: Not only did Zachary Quinto have to embody Spock, one of the most beloved sci-fi icons of all time, he had to do it while face to face with the original Spock himself, Leonard Nimoy. Thanks to a particularly troublesome glitch in the space-time continuum, the young Vulcan meets his future self in J.J Abrams' exciting but largely illogical 'Star Trek' revamp. We're holding our breath for a Kirk-meets-Kirk scene in the sequel.


2. Mike Tyson in 'The Hangover'
We'd love to have been a fly on the wall as the crew behind this sleeper smash hit on the former heavyweight champ as the pivotal piece of their "what the hell happened last night?" plot. "Everyone says Mike Tyson is a badass, but I think he's kind of a sweetheart," says Stu (Ed Helms) after they survive their run-in with the Phil Collins-obsessed boxer. Of course Alan, (Zach Galifianakis), who's on the unfortunate receiving end of Mike's fist as he completes his flourish to an enthusiastic air drum solo, thinks otherwise. "He's still got it!" proclaims Stu as Alan goes down for the count.


1. Bill Murray in 'Zombieland'
How can you make a rip-roarin' zombie action comedy even funnier? With a kick-ass cameo from the man who knows a thing or two about laughing in the face of supernatural plug-uglies: Bill Murray. It's hard to say what our favorite part of the zombie-hunters-in-Hollywood sequence is: Bill's ridiculously lavish mansion; the joy of watching Twinkie-lovin' tough guy Tallahassee (Woody Harrelson) and Bill playacting 'Ghostbusters,' or Bill's final line about his only regret in life: "'Garfield' maybe."