Jonathan Snook has posted two methods for creating multiple validation sets in the latest version of your CakePHP application.

In CakePHP, you define how your data should be validated by setting parameters on the validate property of your model. In version 1.2, there is an on option that can be set on a specific rule that, when set, is either create or update. [...] Despite that, I developed a slightly different approach that allows for different validation sets to be specified and to be cleanly separated from each other.

He overrides the validates() method with his own in a custom model in one of two ways - having the script check for a validation set for the current controller or by specifying it directly with a validationSet property. Code for both methods is included.