Create activity on profile submit

[danaskallman]

I am looking for examples on how to trigger an activity being creating and a profile submit. On the wiki I see the PostProcess hook:
https://wiki.civicrm.org/confluence/display/CRMDOC40/CiviCRM+hook+specification#CiviCRMhookspecification-hook_civicrm_postProcess

But I am still not fully understanding what I need to do when a profile is submitted to trigger the event. Are there any examples I can be pointed too.

This is to use on a WP site.

[John.K]

I'm struggling with this as well. My main issue is that the $form doesn't store the contact ID of the contact, so we don't know who to 'target' the api call to create the activity at (see http://civicrm.stackexchange.com/questions/213/can-i-find-the-target-contact-id-in-hook-civicrm-buildform)