When Dave goes off to a European business trip, but leaves the boys at home with a sitter, Alvin feels like he will never get to see the world. While at an arcade with the Chipettes, Alvin and Brittany get into an argument about just who could make it around the world the fastest. Their argument catches the ear of two diamond thieves who are trying to figure out a way to smuggle their stash to various points around the globe. So the Chipmunks and Chipettes get hired to do the crooks' deeds (even though they don't realize what is happening).
The two wealthy diamond thieves' plans are pretty simple. The boys will travel around the world dropping off plush versions of the Chipmunks filled with diamonds. As they go to each location, they are supposed to pick up one of the Chipette toys that were left by the girls and stuffed with cash by the people who will retrieve the diamonds.
The two groups will travel from Mexico, to the Middle East, to the Arctic and all around. Each time they make a stop, though, they keep narrowly avoiding disaster as the diamonds' true owner is throwing everything he can at the various stops in order to get back his diamonds. It seems like every time the two teams make a stop, they break out into a song (as Chipmunks are apparently prone to do) and avoid getting their toys stolen from them - though they don't really notice these people trying to take their cargo away until a majority of the film has passed.
Eventually, the six team up to get through the last of their journey and make it back to the states, but it will take all of their effort to escape from the thieves and expose them for who they really are.
All in all, this is a fun adventure full of a ton of songs, both Chipmunk originals and covers of pre-existing songs. Anyone who remembers either this movie or the series it stemmed from will probably want to pick up this DVD to relive those good, old days. As for newer audiences, this adventure is nowhere near as dated as the TV series itself, so it should hold up better to a more modern generation.