This is awesome.
Yoinked liberally from the almighty wikipedia god and an old Roger Ebert review ...
"It Came from Hollywood is a 1982 comedy film compiling clips from various B movies. Written by Dana Olsen and directed by Malcolm Leo and Andrew Solt, the film features wraparound segments and narration by several famous comedians, including Dan Aykroyd, John Candy, Gilda Radner, and Cheech and Chong. Sections of It Came from Hollywood focus on gorilla pictures, anti-marijuana films and the works of Edward D. Wood, Jr.. The closing signature song was the doo wop hit 'What's Your Name' by Don and Juan.
Here is a movie that could save you years of watching the Late Late Show; it's like Creature Features died and went to heaven. It Came from Hollywood is a 90-minute guided tour through the worst parts of nearly 100 of the worst movies ever made, from The Amazing Colossal Man to Zombies of the Stratosphere. It turns 'That's Entertainment!' into 'That's Entertainment???' And now that I've finished with my cornball one-liners, let's get on to the movie.
But 'It Came from Hollywood' goes beyond the Medveds to encompass whole genres of awfulness. It uses montages to show us wave upon wave of flying saucers, tray upon tray of human brains, attack upon attack by savage beasts, and a sequence in which a series of utterly unconvincing giant insects stumble jerkily over cardboard cities.
The movie was been assembled by Malcolm Leo and Andrew Solt, who have made a specialty of compilation films. Their credits include Heroes of Rock and Roll and the remarkable This Is Elvis, in which documentary footage and film and TV clips created an uncanny portrait of Elvis Presley's rise and fall. This time they organize their material into segments introduced by Dan Aykroyd, John Candy, Cheech and Chong and Gilda Radner --whose names are exploited in a very bad advertising campaign that for some reason chooses to obscure the fact that this is a film of highlights from bad films."