Depending on the complexity, each situation is different, If I am just simply moving files around, I'll write a quick batch file. If I want to do something more complex Ill normally just skip the scripting part and write a quick c# program that can handle it.
The question then is do you put that c# program in svn and have it versioned :)
edit: The benefits of a dedicated c# application is that I can reuse code fragments to create new hooks later, including a simple log output I created to handle hook logging.
