I LOVED the TV show Land of the Lost when I was a kid. Who didn't? Here's a piece of advice: if you loved the TV show, go rent the DVDs. If you're a bit younger than I am, and you never saw the show, and you love Will Ferrell's mugging, physical comedy, go ahead and rent this movie.
The movie is full of clever nods to the TV show, most of which I'm sure I missed (It's been a long time since I watched those Saturday morning kids' shows!). Ferrell, with his usual manic zaniness, runs around the set like a madman but somehow pulls of some genuinely funny scenes. I particularly liked the scenes with ultra-lib Matt Lauer. Early in the movie he writes Ferrell's character off as a quack; by the end, he has to eat crow. I can't stand the guy (from a TV/political perspective; I'm sure he's an OK guy otherwise), but it's nice to see he can have some fun in a movie like this.
Bottom line, 1 star.