This paper I think goes into enough detail and looks at the possibility to train cats in groups which could be used to herd cats.
More recently, Electronic Data Systems (EDS) aired a commercial during the 2000 Super Bowl that impressed and amused countless television viewers. Cowboys were actually herding cats, thousands of cats, it seemed, though “about 60 cats were used, each with special skills such as running, swimming and sleeping” (LeSueur, 2000). The rest of the herd was created by computer enhancement.
As also indicated in the paper, cats can become attached to the person that feeds them regularly and will happily follow the owner around if there is the promise of food.
Here is a link to the video on youtube.