1UP interviewed Kenji Kanno, the Chief Game Design Manager of the upcoming Crazy Taxi: Fare Wars. Amazingly, the interview doesn't really ask many questions about the PSP game. Instead, it focuses on general industry and Crazy Taxi series questions. When asked about the most important part about the evolution of the series, Kanno answered, "I wouldn't use the word 'evolution' for this series because basically the whole point of the game is to have a lot of fun in a short period of time."
Sounds like the perfect kind of game for a portable!