As the film debut of Christopher Nolan, Following showed serious promise. While not perfect, its manipulation of time and use of the film noir genre is admirable and proved to be the precursor to his first widely released and superior Memento.
Following is about a man with the habit of following strangers, and what happens when one of them turns out to be a follower himself. The film cleverly mixes up time, showing scenes out of order to raise questions to what later happens to the follower. At the beginning, he's long haired and unshaven, but in other scenes he's cleaned up and others he's bruised and beaten up. It's a wonderful technique to keep the audience involved in the film. We know he must get into some serious trouble, but we don't know what or why. The film's black and white photography, while likely chosen more for its inexpensive trait, complements the film noir aspects of the storyline.
However, mostly due to the small budget, the acting isn't too great. Only the thief character named Cobb whom the follower gets involved with is convincing in his role. Everyone else feels like a B-movie actor, and not very good ones at that. But another downfall of this film isn't much a fault of its own. Nolan's later film Memento tells another noir story in a very similar style, but with amazing fashion (telling the story completely backwards) and a story arc (A man with a memory disorder after his wife was murdered) that far outshines Following's smaller ideas. Here it seems he was just beginning to toy with time and scene order in film, so he'd really get it right in Memento.
Overall, Following is a decent little flick that is better rented before being purchased. Fans of Memento may find it especially interesting to see how the director began shifting time and scenes around in preparation for his later mind bender, but the average film viewer might want to skip it and check out the superior Memento instead.