from http://blog.amtopm.be/2013/02/22/getting-personal-tasks-from-the-user-profile/

Getting (personal) tasks from the user profile.

February 22, 2013 by W0ut

Introduction

On the personal site (user profile) users are able to create new tasks assigned to themselves. However when looking at the site content there is no tasklist to be found.

Turns out that the tasks in the User Profile are stored in a hidden list on the user profile site. The tasks are not even stored as a task contenttype.

Where is it stored?

The list where the user profile tasks are stored is called: ‘WmaAggregatorList_User‘. You can access it by using the default server model (have not tried client model yet)

The special contenttype

But there is more. Look at the contenttypeId of those items: ‘0x0056568DFBB054A24E9CD75205760A1195‘
It does not resemble the typical contenttypeId layout that we are used to. A content type always starts with ‘0x01′ (=item) from which ,normally, all other contant types inherit. It seems that this is a special one.

For you reference here is a list with the default contenttypeId prefixes

The contenttype fields

Here is also a reference to all the fields included in this special ‘item’ contentype