Having compiled the collection of 14 articles, van Leeuwen is enthusiastic and says that the collection gives `a nice impression of the state-of-the-art view of swimming and flight in 2007'. Although he admits that the papers gathered in this issue only offer a glimpse of the fast developing world of fluid locomotion, he hopes that the novel approaches described will inspire anyone fascinated by fish, birds and insects to tackle some of the more arduous questions that have so far eluded us.