user_profile_form

I need to give a seamless implementation of a site, where users can edit a number of bits of information about themselves. The Default form in content_profile is to add tabs (primary or secondary) to the /user/%uid pages. The content_profile_registration module does it right, it allows you to tick a box, and so add the fields to the registration form, using hook_form_alter, to add fields to the 'user_register' form.

Is there a module which does the same for the user_profile_form? or hook_user($op=form, $category=account);