and get access after activation.
Now i need to perform additional actions right after the activation took place.
The user_hook as no op for activation, also thought about adding a rule to the user/reset form but could not find a way to it.
i setup a drupal application where a users can register themselves
Any hints are appreciated.
I am not sure what you want to achieve here. I guess Rules module [1] will help.
[1] http://drupal.org/project/rules